The local music store is letting me borrow a Jupiter Slide Trumpet/Soprano trombone for the week. Do I need one of these? I am a middle school band director, grades 5,6,and 7. It would be nice playing along with my trumpet players so they can't look at my fingering! Next question: Do I play treble clef and transpose or learn new positions for treble clef; ie third space C is first position instead of thinking it as concert Bb, first position?