Complex sentence: His other vocalists included Frank Sylvano, Billy Scott, Arthur Jarrett and Stone beginning in 1929 and in 1932, he added Joe Martin, another of the band's violinists, as a frequent vocalist.
Split into simpler sentences: His other vocalists included Frank Sylvano, Billy Scott, Arthur Jarrett and Stone. In 1932, he added Joe Martin, another of the band's violinists, as a frequent vocalist.