The song is "Sister Janet" by Tori Amos. You should be able to find a lyrics site that will give you the complete lyrics, and you're welcome to use the song to your heart's content. (In fact, I'm such a Toriphile that if you gave me an address, I'd send you a compilation.)

People who are more popular sing less, because they care what other people think about their singing.

Except if being in the choir is elitist. We had a weird kind of popular at my high school in the A'Capella; for example, there was this one boy who literally had a harem, some of whom were upperclassmen!