Where have all the old folk singers gone? Off to Las Vegas if you are to believe Lou Gottlieb of The Limelighters. Gottlieb told the matinee crowd at Wolf Trap Saturday that he's accustomed to working with dozens of chorus girls culled from "the retirement list at the Lido. They're still a lot of fun to work with as long as they're taking their medication."

Gottlieb's expansive gestures ("I'll be acknowledging the bulk of applause here today."), his one-two punchlines ("Mother Superior, there's a case of gonorrhea in the convent. That's good, I was tired of having rose'."), and his trio's up-tempo songs lent the '60s pop-folk concert some much needed verve and color.

The Association opened with a polished but perfunctory set of top-40 hits. Dressed in white suits, they walked on stage looking like they had just looted a men's shop on Fantasy Island. Their intricate harmonies still serve them well, but most of their songs were of strictly sentimental value.

The Kingston Trio, which followed The Limelighters, managed to hold their own. Somehow the same songs, singalongs and old jokes still work for the trio.