It's from 1966, called Evening Primrose, and has a score written by none other than Stephen Sondheim. And it stars...Anthony Perkins. While somewhat of a surprise, this actually wasn't Perkins' first attempt at a musical -- he'd previously starred on Broadway in Greenwillow, written by Frank Loesser, which I've posted video from.
Beyond just these two, though, the show if further intriguing by having its book by James Goldman, who wrote the play (and movie) The Lion in Winter, as well teaming up with Sondheim again a decade later for Follies.
And co-starring opposite Anthony Perkins is Charmian Carr, who most people know from her movie performance the year before as 'Liesl' in the Oscar-winning movie of The Sound of Music.
The story of Evening Primrose is decidedly offbeat, though "odd" might be a better word. A disillusioned man accidentally comes across a secret society of people who live in a department store and quickly falls in love with their leader's young maid, though unaware that there might be some sinister underpinnings of this secret world. Most notably that once you decide to become a part of it, you don't leave.
This is the song that Perkins sings with Carr, "Take Me to the World."
By the way, there's another bit of interesting history with this show. Seven years later, Perkins and Sondheim teamed up to write the screenplay for the mystery-thriller, The Last of Shiela in 1973. And I'm wondering if this production of Evening Primrose is where they met. Incidentally, the iMDB database shows that a remake of the movie is in development.