I have a trio that includes a trumpet, guitar/trombone or tenor sax and me. I set my x1 to turn on 1 whole step down. That way both the trumpet and sax player can play out of the same fake books that I used when I learned the song. Once I learn a song I don't need the music anymore.

I also use the transposer to put songs into my vocal range. 1 whole step down works for me for a lot of songs. If I do a Beatles tune I usually dial it down 2 whole steps. I play "Yesterday" in F but sing it in D.

The transposer is a great invention!

Tom