For Mostel, Fiddler was his third, and biggest, theater success of the 1960's, beginning with Eugene Ionesco's absurdist play Rhinoceros in 1961, followed by A Funny Thing Happened on the Way to the Forum in 1962. In a reversal of the plot surrounding Mostel's role as a failing Broadway producer in Mel Brooks' 1968 debut film, The Producers, investors in Fiddler made $1,574 for every dollar invested.
My parents took me to see Fiddler when Zero was still in it and I still remember the event (which I believe was mandatory for every Jewish family in the New York metropolitan area because so many of our families emigrated from that part of Russia amidst the turmoil of those times). There is nothing on YouTube from the original Broadway cast but I found this from his appearance at the Tony Awards show in June 1965. You can see for yourself what a force of nature Zero was onstage. It's also the reason he was not cast in the film version of Fiddler. The director felt that anytime Mostel was onscreen he would draw all the attention to himself to the detriment of the other performers.
Fiddler on the Roof continues to be performed around the world. It is particularly popular in Japan which at first glance seems odd but the author of a recent article in Tablet explains:
Fiddler opens with a song celebrating tradition, but the bulk of the show is about the difficulty of maintaining those traditions—and, perhaps, the futility of trying—in the face of a modernizing culture. And it ends with the family, filled with a mix of hope and fear, taking off for whole new world(s) where the old rules don’t apply and the new rules, if there are any, are not yet clear.
So maybe Fiddler resonates in Tokyo not only because it’s a family drama about fathers and daughters, or a universal tale about modernity, but because Japanese history does, in fact, include a chapter about dislocation from a sepia-toned “old world” and an uncertain journey to a “new world” where the traditional rules no longer applied. Tevye and his daughters had to leave Anatevka and even move across an ocean to find their new world. The Japanese stayed put, but the new world came to them just as surely, with the same uncertain mix of hope and fear.