The amount of attention paid to the latter artist in terms of biographical research, including the histories of his sidemen, means that for Hartwell to drop off the face of the music scene entirely must have taken considerable enterprise. It is known that in the spring of 1925 he left Beiderbecke and headed for Miami. He began playing mostly reed instruments at that point, took charge of his own band but also worked as a sidemen in Joe Strum's Miami Beach Band. He became a bassist in the '30s because of an asthmatic condition and was associated with several hotel bands including one led by Carl Springer during the second World War. After this the trail ends; in a '70s biographical reference written by John Chilton he was already consideredto be deceased. ~ Eugene Chadbourne, Rovi