This Zeffirelli film is also available as a staged version from the Met (well, it is on VHS!). It's paired with a first half Il Tabarro, by Puccini (also Juan Pons and Teresa Stratas).
The staged version has a one Luciano Pavarotti singing the clown; but the show is almost stolen as Pons appears in front of the curtain in order to sing the prologue aria, quite brilliantly.
Yes, this was a 'Gala feom the Met' - sometime in the mid 1990s. Domingo played the tenor role in Il Tabarro, and Pavarotti in Pagliacci. Juan Pons and the soprano (was it Stratas?) were in both.
I agree with you that Pons is superb, not just in the prologue of Pagliacci but throughout the whole thing, and also as Michel in Il Tabarro. I think the mid 90s were absolutely his best years, vocally, but he is also a terrific actor.
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"Maybe I should go alone"
- Quint, Jaws.