In the world of pop music, there are two kinds of "new" sounds -- old-new sounds and new-new sounds. With musical trends and fads coming and going at breakneck pace, performers are often stuck with keeping on top of the game. The worst sin for musicians of this sort is to be playing a new style that is no longer, well, new.

Such is the case with Los Microwaves, a San Francisco-based group that appreared at the 9:30 club Saturday night. Their show was a catchall of old New Wave styles -- the machine-like vocals of Devo and the pounding dance beats of the B-52s were presented intact, with no new harmonic or rhythmic accents.

The three musicians clanked about the stage in the once-fashionable robot movements, uttering stale denunciations of television, admen and urban life in general. They were aided by an electronic rhythm machine whose precise accompaniment was the high point of the show. Los Microwaves might think they are presenting a fresh musical offering, but all they are serving up is cold leftovers.

Washington's very own Insect Surfers opened the evening with music that was so old it had to be new. The group has taken the "surf sound" of the '60s and updated it with a heady dose of straight-ahead '80s rock. The result is both witty and imaginative. Now, if only they could end their songs together and maintain a steady beat. . . . Still, the Insect Surfers are an engaging bunch of pests to have around. Hold the Raid.