Offering a set of solo improvisation for drums and percussion would seem to be a promising way of emptying a performance space; but those streaming for the exits would clearly be people unfamiliar with Jerome Cooper, who applies a particularly judicious sensibility to his instruments. In so doing, he plays against type. Even in a combo, and even if that combo is steadfastly traditional in style and content, it's the drummer who can (and does) most readily approach anarchy in his solo spots. And yet Cooper--whose past work with such musicians as Steve Lacy, Anthony Braxton, and Cecil Taylor marks him as anything but mainstream--does just the opposite: he succeeds by imposing a high degree of order on his solo performances. They start simply and develop clearly, and they eschew the phantasmagorical bashing that elicits cheers from people who see music as an athletic competition. What's more, Cooper's solos keep touch with roots. He proves that a backbeat can still be a backbeat, even when the time is elastic. Lots of other drummers have displayed this knowledge in their solos, but most of them came up before free jazz changed the rules; the Chicago-born Cooper stands out as a thoroughly modern throwback. Saturday, 7:30 PM, Club Lower Links, 954 W. Newport; 248-5238.