Reprinted from yesterday's late editions

Forget "Grease," which is really a '70s story in '50s costume. Forget those radio marathons that purport to be histories of rock 'n' roll. Forget them all, with the exception of Sha Na Na, which almost single-handedly has kept the spirit of early rock 'n' roll (and its kissing-cousins rhythm and blues and rockabilly) alive.

The nine-member band, which wowed a huge crowd at the Merriweather Post Pavilion Thursday is successful because it synthesizes a touch of caricature with an overwhelming love for the innocent, occasionally inane and continuously vibrant music that merged in the late '50s and early '60s.

The 33 vintage classics that Sha Na Na recreate point up a major strength: Everyone in the group is an excellent singer. They show it in the handling of the hilarious bass lines and the high pitch of songs that suggest everyone in the '50s recorded in pants that were just a bit too tight.

Additionally, Sha Na Na has avoided the temptation to embellish.The instrumentation is simple, direct, uncluttered. That also applies to the occasional harmonies, corny humor, the costumes, the hairstyles, the dance contest, the steps, the gritty saxophone breaks. Sha Na Na is a total concept in continuous entertainment. Oddly enough it is also educational, a loving look at recent roots. But most of all it's fun.