Arpeggio substitution is an extremley useful device for creating interest in solos, and to help keep your lead playing from sounding like a load of boring scales.
If you wanted to solo over an A minor(Am) or minor seven(m7) chord, the obvious scale choice you’d normally come up with would be A Dorian. Playing this scale would sound fine of course, but after a while would become rather dull, especially if you’re soloing over a lengthy one-chord vamp; and you’d probably end up just running up and down the scale. A one-chord vamp, however, is an ideal opportunity to get down to some arpegio substitution, to keep interest alive. So, what is it and how does it work?
Well, if you take the notes of A dorian you’ll find you have A B C D E F# G, and you can form a seventh arpeggio on each degree of that scale, by skipping the second, fourth and sixth notes, and using the first, third, fifth and seventh notes from the note you started on. So, starting from A, you get A C E G: an A minor seventh(Am7) arpeggio, and starting drom the B you would have B D F# A, or a B minor seventh(Bm7) arpeggio, and so forth. So you should end up with the following arpeggios from each scale degree:
A : A C E G (Am7 arpeggio)
B : B D F# A (Bm7 arpeggio)
C : C E G B (Cmaj7 arpeggio)
D : D F# A C (D7 arpeggio)
E : E G B D (Em7 arpeggio)
F#: F# A C E (F#m7b5 arpeggio)
G : G B D F# (Gmaj7 arpeggio)
Playing these different arpeggioes over an Am7 chord will give you different harmonic results, as shown below. Notice that some arpeggios are shown in bold: these are built on the original chord tones of the Am7 chord, and so will be easier to ‘resolve’ – however, the others are well worth experimenting with too, they just require more care if they’re to sound effective...
Am7 arpeggio over Am7 = Am7
Bm7 arpeggio over Am7 = Am13(no 7)
CM7 arpeggio over Am7 = Am9
D7 arpeggio over Am7 = Am11(no7)
Em7 arpeggio over Am7 = Am11
F#m7b arpeggio over Am7 = Am6
GM7 arpeggio over Am7 = Am13
This creates an illusion of ‘jazzier’, extended chords, instead of just the same old Am7. For example, as you can see above, playing a CM7 arpeggio over Am7 creates an Am9 sound, or using an F#m7b5 arpeggio creates an Am6 effect. Of course, if you stick to just one arpeggio shape, say CM7, you will create the effect of just one extended chord(in this case Am9) throughtout, so the trick is to mix together different arpeggios to create an impression of different chords and shifting harmony, to keep the listener interested(or riveted, hopefully!). Arpeggio sustituion works especially well with chromatic notes, especially when shifting between arpeggios, or to break out of a rut you may have got yourself stuck in when using a more scalic aproach to soloing.
Incidentally, the quickwitted ones among you may have spotted that all the notes in the above arpeggioes are in the A dorian scale which we chose in the first place anyway, and are wondering why we can’t just use that? Well, you could, naturally, but thinking in terms of scales can tend to just sound like a technical exercise: the whole point of this lesson is to help break away from sounding like you’re practicing scales in your solos: arpeggio substitution is a tool to assist you in making more intersting and original note choices that you wouldn’t when thinking in terms of scales. Obviously,you can still use scale-based licks from A dorian as well – try mixing them up with the different arpeggios and add chromaticisms, and see what happens...
When I get round to it I’ll provide a table of what arpeggios to use in place of which scales, and some fretboard shapes for the different arpeggios, but until then I’m afraid you’re on your own! Good luck!