In this week’s free Irish guitar tutorial from Folk Friend I will be running you through a very popular modern session jig called Donegal Lass, written by Brian Finnegan of Flook fame. I will be showing you how you can analyse a melody by ear and quickly pick out the best chords to accompany it! I will also run you through basic guitar chord substitutions that you can use to add variation to your Irish guitar backing. This is also applicable to Scottish and Welsh folk music (and that of most of north western Europe).
This week on Folk Friend’s weekly Celtic guitar tutorial video I’ll be running you how to pick chords for Irish, Scottish and general Celtic music in the most common type of minor key, the dorian mode.
This week’s free Irish guitar lesson from Folk Friend is for complete beginners who want to learn how to accompany Irish traditional music on the guitar by ear. I’ll be showing you which chords fit with a tune in a major key and how you can train your ears to recognise where those chords should fit. I’ll also be giving you some examples using my free playalong video with on screen guitar chords for a classic Irish reel called Maid Behind The Bar. You can find that video here:
This tune doesn’t have any strong chord IV sections in the A part, so in the simple version I have simply stuck to the “folk formula”- chord V on every seventh foot tap, resolving to chord I at the end of each section. The B part’s third and fourth bar very clearly outline a G major chord. The notes of the melody here are G A B D B A, G A B D B D. The notes of a G major chord are G, B and D. NB- when picking chords to accompany a tune, the most important notes to listen to for chord choices are the ones on the dominant beats which I have written in bold text. In the interests of simplicity for the beginner guitarist I have used E minor instead of G major- this is valid as E minor is G’s related minor, so the two chords can be used interchangeably. Aside from these two bars, the B part also follows the standard formula.
In the A part of the tune I have switched A minor to F major. This is actually a chord borrowed from the aeolian mode. In the key of A dorian, the F chord should be an F# diminished as in A dorian’s related ionian mode, G ionian. However if we were in A aeolian the 6th chord would be F major. A minor chord can always be substituted for either the chord which is two above it in the scale (its related major chord) or that which is two below it in the scale (another chord with which it shares two notes in common). In this instance I have used the chord two below as it would be in the aeolian mode instead of as it would be in the dorian mode. The reason that this nifty trick works is because there is only one note different between the dorian scale and the aeolian one. Compared to a major scale, the dorian mode has a flattened 3rd and flattened 7th while the aeolian has a flattened 3rd, flattened 6th and flattened 7th. It is this flattened 6th which gives the aeolian mode its darker character than the dorian. By borrowing the F chord from A aeolian, your accompaniment will give the tune a darker flavour than it would have had if you had used the F#dim (or a substitute thereof) which you would expect in the dorian mode. You can get away with this in the third bar of the Cliffs of Moher because there is no 6th note in the melody anywhere in this bar. This is a common feature of Irish melodies, that in minor (dorian or aeolian) tunes, the 6th note rarely appears, meaning that you can often use the chords of either the dorian or the aeolian mode, or a combination of both, for artistic effect. You can find out more about this technique in my free video on the subject here.
In the B part I have followed the G chord outlined in the second bar, and then replaced it with its related minor (Em) in the third. I have substituted an F (again, borrowed from the aeolian mode) for the A minor in bars 5 and 6. Bars 7 also outlines the notes of a G chord, so I’ve added one in.
In this version, I wanted to go for a “gypsy jazz” flavour, so I have begun with the “Django chord”, aka an A minor add 13 (I’ve notated it as Am13 on the video to save space- the difference between an actual Am13 chord and this Am add 13 chord is that Am13 should contain the flattened 7th note, G, as well as the root, ♭3rd, 5th and 13th, but this chord does not).
I have replaced the F majors throughout with F major 7. This F chord is borrowed from the mode of A aeolian. A aeolian is related to C ionian and therefore has the same chords as that mode. In C ionian, F would be chord IV and therefore if you wanted to play a tetrad (jazzy 7 chord) for it, it would have to be F major 7- hence that is the chord which I have used in this context.
Once you have descended into jazz land, any chord which resolves down a fifth can be replaced with a dominant or altered dominant chord. For this reason I have replaced my chord Vs in this version with an E7#5 chord. This is a really classy chord V and, due to its flattened seventh and altered chord tone, the #5th, very much sounds like it wants to resolve back to chord I immediately afterwards (resolving down a fifth, from V to I).
When the A part repeats, I have made a change to the chords for contrast. In the 5th bar of the A part repeat I have borrowed the D minor chord from A aeolian (acceptable as there is no 6th note of the A dorian scale in this bar of the melody) and played an ascending aeolian chord run from the Dm7 – Em7 – Fmaj7 before ending the section with my altered dominant V – I.
For the B part I have used a more traditionally dorian set of chords. Whenever you are playing in any mode other than ionian, chord VII becomes a dominant chord (9, 11 or 13). For this reason I have used G13 in the third and fourth bars. I also like G13 and Am add 13 together as they are particularly easy chord shapes to switch between at speed.
The D9 chord used in bars 7 and 8 gives the section a characteristically dorian feel. Recall that A dorian contains the same chords as G ionian, meaning that the IV chord in the dorian mode is equivalent to the V chord in the aeolian mode, and therefore has to be a dominant 7 type tetrad. For this reason my inclusion of a D9 here provides a very clear jazzy dorian vibe.
When the B part repeats, the tune contains a section in bars 5-6 of the repeat which is basically a descending scale from the 5th (E) down to the second (B), punctuated with E notes (E – E D E E, C E E B E E). I have sought to replicate this descending figure in my chords by descending from Fmaj7 to Em7. The next bar is an ascending scale and includes the 6th note of the A dorian scale, F#. For this reason I have played D/F# in my chords for this bar. As that sets up an ascending bassline from E – F#, it seemed right to use G13 instead of an Em or E7 type chord for the last chord V section. This continues the upward motion in the bass and then takes me back to my root note, E – F# – G – A.
The basic chords for this one are fairly self explanatory. For simplicity’s sake (and thanks to their similar melodic structure) I have used the same loop for the A and B parts.
Bar four is a “seventh foot tap” section and consequently takes chord V, but bar III also sounds like it needs chord V. Its notes are “D G G F# G – A B”. G, B and D, which make up the bulk of this bar, are the notes of chord VII, chord V’s related major chord. This section is therefore firmly in the chord V family. A similar principle applies in the equivalent bar in the B part.
In this version I have substituted A minor to its related major, C major in the second bar. I have replaced Em with its related major, G, in bar three before reverting to E minor in order to make the V – I resolution nice and definite at the end of the section. For a bit of variation I have put Em and G the other way round in the second half of the A part. As before, this progression is also applied to the B part.
In this version I have added linking chords between each chord and its related minor. The way these chords work is that in order to link any minor chord to its related major, or any major chord to its related minor, you take the chord one below the lower of the two and play it in its first inversion as a linking chord. For example, to link A minor to its related major, C, you take the chord which is one below A minor, aka G, and play it in its first inversion, giving you G/B. The B at the bass of this chord acts as a nice little bassline to link Am to C (A, B, C). On the subject of G/B, the chord I give below as G/B has an extra note in it, but for ease of naming I have ignored it. Strictly speaking it should be called Gadd13/B. …Catchy!
Further on, the same technique has been used to link G to its related minor, Em. The lower of the two chords is Em, therefore I use the chord whose root note is one below it in the scale, in its first inversion. One below Em is D, so I use D/F# (D in the first inversion) as my linking chord to join G to Em. This would also work as a link in the reverse direction, linking Em up to G.
This tune is in the key of G ionian. This means the available chords are G major, A minor, B minor, C major, D major, E minor and F# diminished, with the main ones being I, IV and V aka G, C and D.
There is a key change in the B part, to A dorian. The chords in this mode are the same ones available in G ionian, but because we are now beginning and ending our key scale on A, the main chords are I, IV and V beginning from A, aka A minor, D major and E minor.
There are no strongly chord IV sound sections in the A part of the tune, so I have stuck to chord I (G) throughout. Chord V, as always, goes in bar four and in bar eight chord V returns to chord I to mark the end of the section. This is the “seventh foot tap rule”- you tap your foot twice in each bar and on every seventh foot tap there is always a chord V.
In the B part we have switched keys to A dorian. You can tell because the first bar contains the notes “E A A G A – G A”. You generally work out which chord family fits with a section of melody by which notes are played on the dominant beats (the ones where your foot taps). In this section the dominant notes are E, A, A, G (followed swiftly by A). As A, C and E are the notes of an A minor chord this clearly shows that a shift to A minor has taken place. The most common of the two minor modes in folk music is the dorian (optimistic minor) and A dorian contains the same notes as G ionian, so it is safe to assume that the B part is in a dorian not A aeolian. This is later confirmed by the inclusion of the F# note which would be F♮ if the part were in A aeolian.
The third bar of the B part starts and finishes on G, so I have put a G chord with it. Resolving from G – Am (chord VII – chord I) instead of Em – Am (chord V – chord I) in the fourth bar works because G major is related to E minor. Every minor chord has a related major chord, which is two above it in the key scale, and these two can always be used interchangeably. In this case E is the 5th note in the scale of A dorian. Two notes above E in the scale is G, so G major can replace E minor for a lighter feeling chord progression.
In the last two bars of the B part you will noticed that I have not ended on A minor as you would expect for a section in the key of A dorian, but on D. This is because I know the tune is about to switch back to G ionian for the A part, so I end the section on G’s V chord, which then wants to resolve back to G to start the next section. Any time a key change is coming up you can always end the current section on the upcoming key’s chord V in order to make the modulation (key change) work.
In this version I have replaced G in the second bar with its related minor, E minor. In order to link these two chords together, I have played an intermediate chord D/F#. This works well because the bass note in the second chord creates a nice bassline – G, F#, Em. It is always nice to link a major chord to its related minor in this way- you can find a complete list of these types of linking chords in my first book, Backing Guitar Techniques For Traditional Celtic Music.
Replacing the G from the third bar with a C works because you can always replace a chord I section with chord IV, or a chord related to chord IV. Therefore, either C or its related minor Am are valid substitutes for a chord I section. In this instance I have linked C to Am using another linking chord, G in the first inversion, otherwise known as G/B. You can find a diagram for this chord below.
I have also used the G/B chord to create bass movement in bar seven. This chord sounds fine in context because it’s an inversion of chord I, and this is a chord I section.
In the B part I have used two minor substitutes for G major in bars three and four. G major’s related minor is E minor, and a major chord can also be substituted to the minor chord whose root is two above its own in the key scale. In this case that is B minor (G – A – B).
The last two bars of the B part use a chord progression which would commonly appear in G ionian, to make it clear that the tune still has its roots in that mode; C – D. This would be chord IV – V in G ionian, and would traditionally be followed by G major (chord I). In the first playthrough of the B part the last chord is A minor as the tune is going to continue in that key, but on the second playthrough it reverts to G major ready for the A part which is back in the original key of G ionian.
In this version I have added nice jazzy tetrads (four note chords instead of the usual triads or three note chords). When adding tetrads or more complicated “jazz” chords into folk music in major keys, chords I and IV become major 7 type chords, chords II and VI become minor 7 type chords and chord V becomes a dominant type chord. You can learn a lot more about how to implement these types of chords in my book Backing Guitar Techniques for Traditional Celtic Music. For our purposes the complete list of available tetrads is: G major 7, A minor 7, B minor 7, C major 7, D (dominant) 7, E minor 7 and F# ½ diminished (again, if you want to understand what a “half diminished chord” is then please see my book).
For the A minor 7 chord in the B part, I like to use the barre chord version (pictured below). I then like to use the high E minor and B minor barre chords which are nearer to this chord than the more common voicings found lower down the neck. Generally speaking, B parts are usually higher pitched and more energetic than A parts, so I often match this by using higher chords (incorporating low open strings as bass notes where possible) in my backing.
In bar four of the A part I have used D9 instead of D7. You can theoretically add ANY notes to a jazzy chord V in a major key, so any dominant or altered dominant chord would do. However the ones I particularly like the sounds of are 9 and 13 chords. Experiment with using these chord types in place of V chords in other keys!
In bar seven of the A part I have used the chromatic link Cmaj7 – C# ½ diminished – D9. This works well because any time you have two chords whose root notes are separated by a tone, you can always link the two by using the diminished or ½ diminished chord whose root lies on the semitone in between them. This works well if you are ascending- if you wish to create a descending chromatic link then using a dominant 7 chord works better, eg D9 – C#7 – C major 7.
In the B part I have used the same tricks mentioned above to convert my substitutions version of the tune into a jazzier version of the same progression. Note the chromatic link reappears in bar seven.
This tune is in A mixolydian. This means that the complete list of chords with which you would expect to accompany it are the same ones available in D major, but beginning and ending from the A chord. Therefore your complete list of likely chord choices would be A major (or A7, as this would be chord V in D ionian), B minor, C# diminished, D major, E minor, F# minor and G major.
The melody uses a trick common in Irish tunes and changes the flattened seventh note from the A mixolydian scale to the normal seventh from the scale of A major / ionian in the final bars of each section. This means that your chord V becomes E major in these bars only.
Bar 3 has to take a G chord (chord VII) or its related minor, Em, because the tune notes clearly outline a G chord (G B D G – -). Bar 4 more or less outlines a B minor chord or its related major, D (B D G B – -). I have plumped for D as I prefer its bright, optimistic sound and it is easier to play!
Bars 1 and 2 of the B part contain the same notes, and hence the same chords, as bars 3 and 4 of the A part.
The tune is somewhat unusual in that the fourth bar of the B part does not have a chord V section, but simply outlines an A chord throughout. However the section does finish with a clear chord V – I cadence as usual. You can tell that the final bar of the A part needs chord five as it contains the seventh note of the A major scale. The seventh note is a very unstable tone and appears in the fifth chord- A major’s seventh tone is G#, which is the major 3rd of A’s chord V, E major. For this reason you can usually take it as a given that a bar containing this note on a dominant beat or for any longer than a quaver is a chord V bar.
In this version I have inverted the D chord in the fourth and eighth bars so that its 3rd, F#, is at the lowest pitch within it. This makes my chords sound more coherent as the large jump in bass notes from G all the way to D is replaced by a smaller gap of 1 semitone from G down to F#. To play this chord, make a D major shape and then loop your thumb around the back of the neck in order to fret the second fret of the bottom E string.
In this version I have substituted A to A7. This works because the mode of A mixolydian contains the same notes, and therefore chords, as the mode of D ionian (major). In D major, A would be chord V and when we begin to use tetrads, four note jazzy chords with 7ths in them, the V chord in a major key is always a dominant chord. This also means that the I chord in the mixolydian mode is always dominant.
Chord VII, G, has been substituted to G7. This is because in every mode other than ionian, chord VII becomes a dominant 7 chord if tetrads are being used. Strictly speaking, the D (IV) chord in the fourth bar should be a major 7 type chord, but I have borrowed the use of a dominant IV chord from blues. This works ok, because the note in the D9 chord which is not in the scale of A mixolydian is a C♮, and there is no C# in the tune in this bar.
The A part of this tune is very standard and has no sections which really sound like they need chord IV. Chord V goes in the fourth and eighth bars exactly as you would expect, returning to chord I to mark the end of the A section in bar eight. However, the B part is very unusual in that it clearly has to begin on chord V, and stay there for a whole four bars! The notes in the first bar of the B part for example are E AAA- all notes taken from an A major chord (A, C# and E).
As I got bored of playing D for two whole bars, I have replaced the second D bar with the same chord in its first inversion. This is basically like playing the same chord but adding a bassline for a sense of movement.
Bars three and four were previously both bars of A. If you have a long period on one chord you can always work your way round the circle of fifths in order to LAND on that chord. In this instance I have resolved down a fifth to A from an E chord (E-D-C-B-A). As we are in the key of D ionian, the E chord has to be E minor (use your Amazing Mode Wheel to check the chords available if you can’t remember them), leaving my previous chord block of A / A / to now become Em / A / . The A chord then resolves to D, continuing on around the circle of fifths. Chord progressions which move round the circle of fifths in this way are very satisfying to the listener and a II – V – I progression like this one (Em – A – D) is a common way to finish sections in all kinds of music.
Firstly, in this version I have replaced all the chords with “the right kind of seven chord”. For tunes in a major key this means that chords I and IV can become major 7 chords, chords II, III and VI become minor 7 chords and chord V becomes a dominant 7 chord. Both Bm7 and F#m7 are valid substitutes for a D major chord- B minor is its related minor chord and F#m is the minor chord two notes above the major chord, which consequently contains two notes in common (D major is D, F# and A and F#m is F#, A and C#).
In the B part I have replaced a long section of A with a nice slidey chord run which is outlined below. I have finished it off with an E9 chord. This works because any dominant or altered dominant chord can theoretically replace chord V, aka 7, 8, 11, 13, #9, ♭9, 7♭5 or 7#5 (bear in mind that some of these options might sound TOO jazzy in some folky contexts).
This tune is in the key of G ionian, and therefore has G major, A minor, B minor, C major, D major, E minor and F# diminished as its chord options with G, C and D being the main ones. I always like to start out by breaking a tune down into “chord I sections”, “chord IV sections” and “chord V sections”. In the A part there aren’t any sections which really sound like they NEED chord IV. That means that most of the tune could have been accompanied by chord I (G), but I thought this was a bit dull, so I have thrown in a bar of chord IV (bar three), which works nicely because any time you have been playing chord I for a while you can always throw chord IV in for a bit of variation.
The final bar of each line has to be chord V (D). This is because the V chord always goes on every seventh foot tap, aka every fourth bar. You will notice that, unlike most tunes, McMahon’s actually has no V-I in the last bar of the A part (bar eight), but instead stays on chord V for the whole bar. The tune actually ends its A part on a long D note, and consequently sounds like it should stay on chord V instead of returning to chord I to make the section sound finished as most other tunes would.
McMahon’s is something of an unusual melody and can be quite tricky to find the right chords for. The B part changes key, to A dorian. A dorian contains the same notes as G ionian, but you can tell the mode has changed as there are suddenly far more As and Es (A dorian’s root and 5th) on dominant beats of the melody, making the section feel a lot more A minor-y and a lot less G-y! In the dorian mode the main chords are chords I, IV and V as normal, but chord V can also be replaced with its related major if you prefer a less dark sound. For that reason I have broken this part of the tune into chord I (Am), chord IV (D) and chord VII, which is chord V’s related major (chord VII is G, the related major of E minor). You can gain a much better grasp of how and why chords fit together using the Amazing Mode Wheel, available here.
As we are now in the key of A dorian, I have begun the B part on A minor. The third bar is pretty vague in its tonality- its notes are “E B B B G – F# G”. To me this sounded most like a G chord (G, B and D) but really I’m never too sure with this tune whether there is really any right answer! The fourth bar is a bit more clearly a G major section; “E B B A B – – -” . We would expect a chord V in this bar for our seventh foot tap, and chord V (Em) in the dorian mode can always be substituted to its related major chord VII (G) for a lighter sound, so another bar of G is a good fit.
In the B part’s final bar, the tune is transitioning back to being in G ionian. For this reason I have ended the section on chord V from the original key of G ionian, aka D major. This makes the transition back to G seem natural.
In this version, I have added a G/B chord, otherwise known as G in the first inversion. This is a very common technique, which creates a nice linking bassline from G up to B and then on up to C. A G major chord normally contains the notes G, B and D. It doesn’t matter what order you pile the notes within the chord, but it is traditional to have the root note at the lowest pitch. For example G, B, D, G, B, G or G, D, G, B, D, G would both be valid G major chord voicings. If you invert the chord so that its 3rd, B, is at the lowest pitch within it then the chord is said to be “in the first inversion”. To play chord I, chord I’s first inversion, then chord IV is a very common technique in folk backing and will work in any key.
In bar six of the A part I have replaced G major with its related minor, E minor for a darker variation. Any chord can be replaced with its related minor at any time, unless it is chord V in a major key which has to be chord V and cannot be substituted.
In the B part, I have capitalised on the vague tonality of the tune to put in a more “pop music” type chord progression. For example the second bar contains the notes “D B B A B – – D”. This could be seen as the top of a G major chord with an A thrown in, so I’ve stuck a G in there instead of the A I went for in the previous version. The third bar contains; “E B B B G – F# G” which is so vague as to be basically a free for all. I decided to go on round the circle of fifths from G to C as progressions which go up in fifths always sound nice and this is basically a chord I section which means you can put anything from the chord I or IV families here without any adverse effects!
Basically there are so few clearly defined chords in this section (each bar contains notes from multiple chord families) that I have simply plumped for a chord progression which sounds good in its own right, and more or less fits with the melody.
In this version I have converted each of the chords from the substitutions version to a jazzier version of the same. When adding tetrads (four note chords) or more complicated “jazz” chords into folk music in major keys, chords I and IV become major 7 type chords, chords II and VI become minor 7 type chords and chord V becomes a dominant type chord. You can learn a lot more about how to implement these types of chords in my book Backing Guitar Techniques for Traditional Celtic Music.
Therefore in my version, G major becomes G69, the quintessentially gypsy jazz sounding substitute for a major chord (replacing chords I and IV in a major key with 69 chords always sounds nice). In bar two, B minor is a substitute for G major, because a major chord can be substituted for the minor chord two degrees below it within the key scale (its related minor- in this key G is related to Em) or the one two above it in the root scale (in this case G can sub to Bm). As we are in jazz-chord territory I play Bm7 instead of plain Bm. As the following bar’s Am has become A minor 7, and this chord is an identical barre chord to Bm but two frets lower on the neck, I have slid down and played the intermediate chord on the way to provide a nice chromatic link, Bm7 – B♭m7, Am7. Finally I have used D9 in place of chord V, because chord V always becomes a dominant 7 type chord when you get to jazz land, and adding any extra notes from the root scale always makes a jazz chord jazzier! In this case a D7 chord would contain D (root), F# (major 3rd), A (5th) and C♮ (flattened 7th). The 9th note in a D major scale would be E, and E is also in our key scale of G ionian so adding an E note to my D7 chord to give me E9 sounds good. As a general rule, using a 9 chord (D9, A9, etc) in place of chord V in a major key pretty much always sounds great.
In the B part, I have more or less taken the chords from the basic version and converted them into the right kind of tetrad. Recall that the chord options for A dorian are the same as the ones in G ionian. This applies in tetrad land too, so the complete chord options are G major 7, A minor 7, B minor 7, C major 7, D (dominant) 7, E minor 7 and some sort of substitute for F# diminished. As we are in A dorian, chord I is Am7, chord IV is D7 and chord V is Em7.
This tune is in E dorian, which contains the same chords as D ionian. This means that the chords available are D major, E minor, F# minor, G major, A minor, B minor and C# diminished. The second bar contains an outline of a D major chord for its second half (A F# D, aka the notes of a D major triad in reverse order) so I have put a D chord there. Chord V (Bm) would normally go on every seventh foot tap and resolve back to chord I (Em) at the ends of sections, but I have replaced this with its related major, D, because this is easier to play. This can be done in any mode which has a minor chord V, aka any mode other than ionian.
In the B part, bar 2 contains the notes F# A G F# E D. As the dominant beats (marked in bold) are both F# notes, which appear in chord IV, D (D, F# and A) I have put chord IV in this section. Rather than have another block of Em straight after, I have substituted the Em to its related major, G major. Bars 7 and 8 of the B part contain the notes “E D C# D – A B A G F# G A”. This is a decidedly chord V sounding section, with D, B, F# (notes from D or Bm chords) making up its dominant beats. Hence I have put two bars of D here instead of sticking to the usual formula of just putting chord V (Bm) or its related major (D) in the 8th bar. In fact playing Em for bar 7 and Bm or D for bar 8 would have worked equally well, but I like the sound of the extra bar of D… And they’re my chords and I can do what I want, so there.
In this version I have switched the chords in bar 4 to be G and A. This provides a bright lift from the E minor root chord and works well as the notes are “D C# B” for the first half (a G chord is G, B and D) and “A F# D” for the second half (the dominant A note sounds cool with an A chord). I have substituted the E minor in bar 7 to its related major, G. This works well transitioning into D (chord V) as any progression which resolves down a fifth will always work well. If you wanted a jazzy flavour you could try replacing the G with a G7, as any time a chord resolves down a fifth you can replace it with a 7 chord for jazzy effect.
I have ended the B part on an A chord. This is a pretty nifty little trick which I like to use in the dorian mode- if you end a section on chord IV it gives the tune a far away, make-believe quality, as if it very nearly achieved its hopes and dreams of dorian corporate supremacy, but then right at the point of success, suddenly decided to give up on the whole thing and go off to the other side of the planet, climb a mountain and become a yak farmer instead. If you want another interesting version of this trick, try beginning a section of a dorian tune on its chord IV and then alternating between this and chord V.
In this version I have used tetrads (7 chords) instead of triads (normal ones). The tetrads available are the same as the ones which would be available in the key of D ionian, aka D major 7, E minor 7, F# minor 7, G major 7, A dominant 7, B minor 7 and C# ½ diminished (in place of which we would usually play D/F#, aka D with a thumb). Additionally, in any mode other than the ionian, we make the VII chord into a dominant 7 too. That means that our complete list of available tetrads for E dorian should be: E minor 7, F# minor 7, G major 7, A dominant 7, B minor 7, C# ½ diminished and D dominant 7. In bar 7 of the A part I have borrowed a C major 7 chord from the aeolian mode. This works because the sixth note of the E dorian scale is not present in this bar, so I can use chords from either the E dorian or the E aeolian mode as only the 6th note differs between the two.
In the B part I have borrowed an A minor 7 chord from E aeolian and used it to create tension by deliberately avoiding chord I. You can always substitute chord IV in a chord I section, but in this case I have deliberately not played chord I at all, in order to make the section feel like it has moved away from its key chord. There is no 6th note in the B part of the tune until the penultimate bar, at which point I am playing chord V anyway which is the same in both aeolian and dorian, so I have treated the whole section as though it were written in the aeolian mode.