People usually point to "West Side Story" and "Gypsy" as Stephen Sondheim's first musicals, which he wrote only the lyrics for. But in actuality, Sondheim wrote both music and lyrics for a musical in the mid-1950s that did not get produced until many decades later, long after he had been established as the messiah of musical theater.

"Saturday Night" may lack the singularity and daring of Sondheim's subsequent work, but it is a well-put-together musical comedy with gorgeous melodies, witty lyrics and endearing characters that holds up a lot better than many 1950s shows that were huge hits.

Set in 1929 Brooklyn among a bunch of hormonal, middle-class, 20-something males, Gene, who is all too eager to gain a foothold in high society, gets lost in ill-advised financial schemes just as he meets the ideal girl next door.

After "Saturday Night" received its New York premiere in 2000 at Off-Broadway's Second Stage, it quickly disappeared, even as revivals of Sondheim's other musicals continued to escalate.

The York Theatre is currently presenting "Saturday Night" as part of its long-running Musicals in Mufti series, which is essentially a scaled-down version of Encores! at City Center. In fact, "Saturday Night" marks the 100th Mufti.

As nicely staged by Stafford Arima, it features an outstanding young cast including Ben Fankhauser and Andrew Keenan-Bolger (both of "Newsies"), Lindsay Mendez ("Godspell") and Margo Seibert ("Rocky"). With just a piano and drums and limited scenery, this intimate kind of presentation is ideal for a delicate but tasteful rarity such as this.

If you go:

3 stars

"Saturday Night" plays at the York Theatre at St. Peter's through Sun. 54th St. and Lexington Ave. yorktheatre.org.