trombtar53

Well lets see...Jazz. Well Jazz can often be hazy, but here are some starters

one very common chord progression- ii7-V7-I . You hear it alot! Pretty much think of some melody that goes with that as a starter. Another thing you can do to spice up this chord progression is a thing called tritone substitution just take any of the chords in that above progression and substitute it with the chord a tritone away...example

dm7 - G7 - C ii7-V7-I
a-flatm7 - G7- C
dm7 - d-flatm7 - C
dm7 - G7 - G-flat

As far as melody, this method is hacneyed of course but mess around with a blues scale...

C-Eflat-F-Gflat-G-Bflat-C or for transposition purposes...1, flat3, 4, flat5, 5, flat7, 1

and above all listen to other jazz. I liked the suggestion of Halleonard.com for marching band...

Have fun!