Good Afternoon. My name is Tony writing from MD. I do have a short question that maybe you can help with.

Im accompanying a piano player who has written a tune in G and then goes to Ab. To me, it seems that the G7 and the Ab7 chords fit in as chord basics but what chords, runs, riffs or anything can I also play to keep the tune jazzy/bluesy?

Thanks for you time.

Tony

Well, if you're accompanying a piano player, you'd better play whatever chords he or she is playing, or it's gonna sound pretty funny! The basic blues chords are I, IV, and V in whatever key you're in, like this:
G: G, C, D
Ab: Ab, Db, Eb.

Certainly making the chords dominant 7ths and/or 9ths will add flavor.

As for scales, do you know the blues or minor pentatonic scales? Here they are:

1, b3, 4, (#4), 5, b7 8
G, Bb, C, (C#), D, F, G

I'll let you transpose it into Ab!!

The note in parentheses is called a "blue note." With it included, the scale is the blues scale. Omit it, and it's called the minor pentatonic.

For a sweeter, happier sound, you can use the major pentatonic scale:

1, 2, 3, 5, 6, 8
G, A, B, D, E, G

And in all cases, adding notes that are chord-tones of the current chord, but NOT in whatever scale you're using, will make it sound like you know what you're doing, rather than just sticking to the scale.

Play on!

Edly