Richard, you're in good company in your piano/trumpet approach.  The Instrumentalist magazine (July 1997) quotes Arturo Sandoval when he says "Whenever I learn a new tune, I go to the piano, never the trumpet.  By the time I pick up the horn with the band, I feel like a fish in water.  I know the chords and where the music is going because the changes are in my brain.  When I close my eyes, I see the keyboard, which helps me pick a good note for a particluar chord.  When I practice the trumpet, I play classical pieces and the Arban, Colin, Clark, and Charlier books, not jazz tunes."

Of course, he's a gorilla.

Doug Ferris
Near Toronto, Canada