At the time I was a high school student in a dramatics class in Brooklyn, and we were often invited to be the studio audience for a NYC Sunday daytime show called American Musical Theatre, which was hosted by Earl Wrightson (a sort of junior-grade Alfred Drake). One Sunday afternoon in 1964 we attended a program devoted to RUGANTINO, the Italian musical comedy that had just opened on Broadway in February. It was the first (and only?) Italian-language musical to come to Broadway, complete with subtitles. After the program, the entire school group was invited to attend that night's performance (unusual for a show to run on Sunday nights).
We all went, and had a tolerably good time. The music was composed by Armando Travajoli, who scored most of the Loren/Mastroianni films of the period, and there was an OCR, which remained in record store remainder bins of the day. Humor was quite broad, and even a bit bawdy for a 60s high school crowd, but reading the titles (sort of like opera house supertitles) was a bore.
The show was only a limited engagement (1 preview and 28 performances) because no one went, and the show had a cast of nearly 50. Oh, and the English translation was done by none other than Alfred Drake!