Not much is known about Johnny Sparrow's background, apart from the fact that he may have come from the South/Southwest, perhaps Texas, and that he first emerged in the reed section of Jay McShann's Orchestra, succeeding Charlie Parker during early 1944. He joined during the group's engagement at the Club Plantation in Los Angeles and played with them through the spring of that year. Unfortunately, the group didn't get to record during this period, and its work has survived best in the form of armed forces radio broadcasts. The band finally broke up in May of 1944 when McShann was drafted. He played with Louis Armstrong's band in 1946 and 1947, and got to record with the group as well. From Armstrong's band, Sparrow went to Lionel Hampton's ensemble, where he was often featured in competition with fellow saxman Morris Lane.