German lutenist and composer Sylvius Leopold Weiss (1686 or 1687-1750) worked with the Scarlattis in Rome early in his life and toured widely through Europe as a young man. During his life he was both the most virtuosic of all lutenists and the most prolific of the instrument's composers, outnumbering any other lute composer with his nearly 600 pieces. Of these, most are in late Baroque style, but later works show development with sonatas and concertos for lute with other instruments. Late in his life, Weiss became a friend of Wilhelm Friedemann Bach, and had an improvisation contest with his father, Baroque giant, J.S. Bach.