"Melodies In The Hills" (PDF) from the Vin Gordon album, Gordon in de Garden, Vol. 1.

Here's another nice tune and arrangement, with an chill upbeat tempo that anyone can enjoy.  A simple melody that goes from major to minor for the A and B sections of the tune.  Also note the slight variation in the chord changes during the solo section.  In terms of arranging, you don't always have to solo over the same form as the rest of the tune, and to go so far as to modulate for the solo, it offers a refreshing sound to the listener and declares a new section of the tune.  Some rock music will go up a half-step, pop music usually prefers the whole step or minor third, and bluegrass uses a move up to the fourth.

This solo is short and sweet, and notice that it barely moves outside a low octave range.  While it's not the most melodic solo, its motifs are strong enough to hold your attention.  The reason is that it is played with attitude.  This goes to show that you do not have to play the highest note or flashiest technique, but rather have a purpose behind what you are playing.  Notice how these phrases set up and move towards the accent note, the punctuation of the idea.

Here is a YouTube video of him playing with the Skatalites:

Recommended Reading: Exercises And Etudes For The Jazz Instrumentalist by J.J. Johnson.  Published by Hal Leonard.