"Grease" is a mostly agreeable musical about the very last moment in time when boys submitted to haircuts (though they were training them to duck-tails), when cigarettes and wine were the makings of girls' pajama parties, when hubcaps were highly thought of as objects worth snatching, and when at least one of the kids around Rydell High ('59) could be heard cursing himself for having forgotten it was Friday and having eaten a hamburger….
The show's state of mind is disarming, its sociology would seem to be accurate (I wasn't in high school at the time), its tunes by Jim Jacobs and Warren Casey are often attractive in themselves as well as wryly nostalgic, and its two principals are so personable and so skilled that I wish the composer-librettists had had the plain good sense to concentrate on them more….
If "Grease" becomes attenuated and rather wearing in the second half, it's because it keeps replaying its atmospheric effects instead of getting on with what probably ought to be the love story. It dawdles over jargon too much, as though just hearing the lunchroom, street-corner, school-gym inflections of the period would be enough to keep us content between numbers. It wastes time on a rumble that's going nowhere and doesn't quite seem to belong to begin with. And it starts up paths—one of the girls gets pregnant—it isn't going to bother to pursue. The book rambles, and has to keep picking up after itself, which is a chore.
But some of the numbers … are worth the waiting even if you didn't graduate from Rydell in '59. Those who did are probably going to be entirely happy. (p. 3)
Walter Kerr, in The New York Times (© 1972 by The New York Times Company; reprinted by permission), February 2, 1972.