Anyone who overlooked the sparse publicity the thrifty Metro Cafe put out for AJ Croce's show should be kicking themselves right about now, resolving to comb the fine print in the Post and the City Paper music listings in the future for mid-week inspiration.Croce brought his keyboards, his voice, and his very capable band to the District last night for a solid show that covered a lot of ground and had the small audience grooving to his blues and roots rhythms. If his name sounds familiar, perhaps you remember that AJ is the son of soft-rock icon Jim Croce, whose life was cut short by a tragic airplane crash in the early 1970's. Although their styles and instruments of choice differ, it's quite clear that son inherited much musical talent from his dad. AJ (for Adrian James) virtually attacks the keyboards with a hammering style that evokes mentions of blues queen Marcia Ball and legend Johnnie Johnson. He has a delicate side, too, and it's clear that he's studied the classics, and the birth of the blues going back to songs from the 1920's. AJ and his band rocked the teeny club for an uninterrupted set that lasted nearly two hours, covering material from his new CD, Transit, as well as his other 3 releases, along with some gems from the past, including a not-so-tender version of Lennon's 'Maybe I'm Amazed', Rod Stewart's 'Stay With Me', and dad Jim Croce's 'Working at the Car Wash Blues'. The meager crowd at the Metro Cafe made it an ideal place for the show. Metro is always intimate, and last night, there was plenty of room for everyone. Croce doesn't come East very often, so next time he shows up, perhaps there will be bigger throngs will come out to become enthralled with his heartfelt performance.