He went on to study with Herbert Sumsion at Gloucester Cathedral, and then with Howard Ferguson at the Royal Academy of Music.
[2] Kellam wrote theatre music for the Royal Shakespeare Company, for the Chichester Festival and for Joan Littlewood.
[5] Balaam, for children's choir and harp, was commissioned by the Aldeburgh Festival as a companion piece to Benjamin Britten's A Ceremony of Carols.
Instrumental music includes the four movement Cassation for woodwind quartet (1964) and After School, a suite of seven easy piano pieces for children.
Kellam was a friend of Peter Maxwell Davies, whom he met when they both played their compositions on BBC Radio's Children's Hour in the 1950s.