lens recomendation

I second the good Professor! For indoor recital type stuff, it's hard to beat the version 1, 2 or 3 Vivitar Series 1 70-210. Also there were some pretty good Kiron made 3.5 & 4.0 70-210 & 80-210 zooms. Most of these can be picked up reasonably. Good luck on your lens hunt.
Regards, hex anon.