Just saw this this afternoon.
Amazing. Best intro ever. Read an interview with the composer. Here's an interesting bit.
"As I understand it, after Lee Van Cleef heard Lee Marvin singing in "Paint Your Wagon", decided that he wanted to sing too. His wife, who was in Madrid with him, had been an opera singer, and encouraged him to have a go. We wrote 2 demos, thinking Yourdan and Gordon would pick one, but they decided on both.
To be honest, he wasn't easy to work with. I think he felt out of his depth as a singer, and covered up by being difficult, which - of course - is not unusual. After 2 rehearsals with me on the piano, he said the piano made him sing out of tune, so a roving English guitar player was hired to be on the set and rehearse with Lee when he had a break.
Funnily enough, his problem wasn't so much about pitch, because we got him to speak a lot of the lyrics, but with the fact that he was "rhythm deaf" - not feeling where the phrase begins or ends, if you know what I mean.
At the recording, the engineer had to cut up his tape and feed it into the proper places to match the orchestral accompaniment."