- He studied piano with Gail Quillman and composition with Stella Roberts.
- Sowerby's chamber music has been championed by the pianist Gail Quillman, who studied with the composer.
- The able and authoritative pianist can be heard on New World CDs of Sowerby's piano works ( NW376-2 ) and trios ( NW 365-2 ) . ( Ms . Quillman is one-third of La Musica Gioiosa Trio, with Karl Davies, violinist, and Margaret Daly, cellist . ) The works are interestingly balanced and lovingly rendered.