He was in season 3e and maybe season two. The nth degree song is at the beginning and the end of a season 3 episode called "there is nothing like a nurse" where all the nurses bug out and the docs stay behind. Thereks another of his songs in that episode.
"And I wonder if they miss us Now wouldn't that be funny? We can hardly stand ourselves. Well it's funny when they're here How we take for granted The way they taste, the way they feel, Their sight, their smell, their sound And it's funny when they're gone And how life can be so empty When they're not around."
And a song called north korean blues I think from rainbow bridge like jeri said. Someone mentioned it earlier.
"Oh Tokyo, They got some saki, and sashimi, and some clean sheets, Oh, kimono, oh, kimono, Tokyo's the town that I love the best, East may be East, and West may be West, Forget about between, it'll drive you insane, And teach you things you never knew before"
He was in one more episode called big mac with 2 more songs.
Five gold stars
"Well it's not Corrigidor, you know it's only Korea, It's a lousy little war, but we'd still love to see ya, And I'm sure we can scrounge up a beach And you can splash in and give us a speech, With your corncob pipe and your five gold stars."
And big mac is coming
"Big Mac is coming, he'll put an end to this war, Oh the U.N. decided it was time for Mac to take it an encore, Oh how I yearn to hear Mac say "I shall return" once more"