Hey Mike,

I began my music performance backing a four piece vocal band. What they often did back then was listen to a brass/woodwind section in a song. From there, one would take the trumpet, another the tenor and alto saxes, and another would take the trombone. Sounds funny, but music is music. Much of what attracts people to harmony is the same whether played on an instrument or sung through a voice.

In addition to learning pitch they also learned other techniques such as swells and other dynamics that were used in vocal bands like, Manhatten Transfer and the like.

Just a suggestion.