It depends. If you can sing on pitch and can sing each part to teach your choir then I don't think so. However, if you have trouble singing on pitch, you or one of your musicians need to be able to play the melody and the harmony parts, together and individually, on an instrument. Usually the instrument is a keyboard or piano but it could be any melodic instrument. In my experience with choirs, also, helpful to be able to play the song for the choir to sing to. If you, a musician, or the band can play the song on an instrument(s) that will help. However, if you can't have live music at your rehearsal and you haven't figured out how to play the song but you still want to teach it, look into tracks just for rehearsal.
