Originally Posted by fresnelly

Okay, here's a request for something little different.

It's a choral work that I would guess is from around the Rennaissance and written for Boys choir.

It's slow and mournful and the notable bit happens when a soloist breaks out from the harmonies to hit this really high note. He holds it for a few beats, then steps down chromatically before rapidly descending back down to the range of the chorus. He repeats that bit a few times and it's what makes the song.

I've heard it more than once and don't believe it's obscure. Any guesses?