Major Lance, 55, a rock singer whose recordings helped shape Chicago's soul sound of the 1960s. Lance had hit singles in 1963 with "The Monkey Time," which started a dance craze, and "Um, Um, Um, Um, Um, Um" in 1964. Both songs were written by Curtis Mayfield. Lance, a Chicago native, started out singing gospel. His break in rock came after appearing on a Chicago television show, "Record Hop." His first single, "I Got a Girl--Phyllis," was written and produced by Mayfield. Lance continued to tour and perform at clubs and music festivals until his death Saturday in Decatur, Ga., of heart disease.