I think he's a great singer/composer. Those 'mumbly' tones sounds fitting for the sadder songs..? But I agree on the part where
I doubt Jay songs are gonna be remembered, much less listened to years later.
meh, if cath needs songs to be sung as a group, I'd go with 朋友 which zgm posted. It's a easy and nice song. or another song which goes
"看到名人总是忙忙碌碌，我的世界。。。“ I can't remember more; I don't really pay attention to male singers at all,because I can't get their keys in singing. zgm might know.