Your excerpts should be longer. As a consumer, there's no way I can make a good decision on whether or not to purchase something after 17 seconds.
That's just me.
Thanks for the feedback, I'll ponder that.
I guess I've been thinking concerning my excerpts that the person listening isn't trying to decide whether or not they like "Total Praise" or whatever other song. They already know they like the song; they're just trying to decide whether I got the alto part right for practice purposes.
Concerning the use of MIDI, that's cool for practice and all. I just hate MIDI sounds, they sound so cheesy. But, I noticed that you used Finale for your excerpts and such. Do you have instrumental excerpts?
For the most part, I don't sell instrumental tracks, just vocal parts. On one occasion someone wanted an instrumental track and I got a friend of mine to do one for them (a real audio file, not a MIDI).