Among the pleasures of Rule Modern and Contemporary Gallery on Broadway are the many New York artists featured there. True, most are little known, but occasionally director Robin Rule is able to snag one of the greats, as she did when an acknowledged master of minimalism was a part of a duet at her venue last summer. The impressive Carl Andre and Melissa Kretschmer combined the classic modular floor sculptures that made Andre a legend in art history with some extremely fine tar paintings done on stacks of glass by his current girlfriend, the much-younger Melissa Kretschmer. Though Andre is considered one of the greatest living sculptors in America (if only for his contributions from the 1960s, when he helped invent minimalism), he is also controversial -- and in a way most artists aren't. He was tried and ultimately acquitted of murder in the death in 1985 of his wife, feminist artist Ana Mendieta. The scandal quotient surely helped spike attendance at the show, but the real stars were the three somber sculptures that Andre had arranged on the floor.