Complex sentence: They began performing with an expanded group and released several records on the Detroit-based Mellow label; by 1943, however, both brothers were in the Navy, with George serving in the Pacific and Leslie in Europe.
Split into simpler sentences: They began performing with an expanded group and released several records on the Detroit-based Mellow label. By 1943, however, both brothers were in the Navy, with George serving in the Pacific and Leslie in Europe.