From a live chat he did while on Days:
Kelly: Hi Jensen thanks for being here! How did you enjoy doing west side story and would you like to do more musical theater in the future? if so, which plays?
Jensen Ackles: I loved it — it was a complete thrill to get up in front of 1500 people and sing in a lead role for the first timever. I was nervous, but I was very happy. It was a rush. I would love to do more. You can’t just mess up and say “cut” and re-do a line.. it’s all on the line. Oh gosh… off the top of my head — Phantom, Les Mis, Miss Saigon, etc., etc.
Kelly: How about Grease?
Jensen Ackles: I would love to do Grease!
Imagine wee!Jensen singing “Tonight” bless him
"Isn’t Harry Potter, like, naked on Broadyway now?"