Watch the >> Fretboard View online guitar lesson by Larry Carlton from 335 Improv
Throughout this course we've been seeing what a big influence rhythm parts have on your improvisational solos. The more options you're able to call on with your comping, the more options you'll have at your disposal for your soling.
In this section, I'll demonstrate how a common blues comping part - a downward half-step slide into the IV chord - can be exploited to great effect using the melodic minor scale.
The blues progression we work with here moves from F# (I chord) to B9 (IV chord). But to create some tension, a blues rhythm part might slide into B9 from half a step above - that is, from a C9. In keeping, your solo could bring out the C9 using the G melodic minor scale. The reason it works is that G melodic minor contains all the notes in the C9 chord.
In any blues progression, you can create a very strong pull to the IV-chord change using the melodic minor. Give it a try over the IV chord here in the key of F#, and then work out where you can apply the melodic minor in all of the other keys.