Convincing John said:
I don't know about anyone else, but sometimes when I listen to the radio or see them on TV, certain musicians sound like Muppets!
What singers sound like Muppets to you?
Well I can think of one singer I've heard a lot in London's West End who frequently has a tendency to sound just exactly like various Muppet characters, but in her case it's absolutely not surprising, because she is one of them anyway.
When I saw:
110 In The Shade, I thought that the character of Lizzie sounded a lot like Raisin in The Secret Life Of Toys.
While in Du Barry Was A Lady, (BBC Radio production) the title character sounded very like a combination of Sesame Street's Ethel Mermaid, and that fish singer that did 'I'm Gonna Catch Me Some Blues' on TMS.
While when it comes to recordings, I've noticed that on the OLC on Nunsense, the character of Sister Mary Amnesia sounds a lot like Annie Sue (except for when she's doing her Country and Western bit), las does the character Ginnie Romaine on the JAY/TER studio cast album of Stop The World I Want To Get Off....
But of course none of these examples count in answering your question. Given that the performer in question is a Muppet anyway.