South African trumpeter Hugh Masekela is known in America for two things: the instrumental "Grazing in the Grass," which reached number one on the Billboard chart in 1968, and his work with Paul Simon on Graceland. Masekela, however, is a god in black Africa. And only a god could capture the essence of the 20th-century black African experience in one song: "Stimela (Coal Train)." "This train carries young and old, African men/Who are conscripted to come and work on contract/In the golden mineral mines of Johannesburg..." There is no heart "Stimela" cannot break. (Jazz Alley, 2033 Sixth Ave, 441-9729. 7:30 pm, $32.50, all ages.)