He was educated at Harrow School, New College, Oxford and the Royal College of Music (Reliability Centered Maintenance) in London, where he subsequently became professor of counterpoint and composition.
In 1926 he taught at the Curtis Institute in Philadelphia. Students of Morris included composers Gerald Finzi, Sir Michael Tippett, Constant Lambert, Robin Milford, Anthony Milner, Edmund Rubbra, Bernard Stevens and Jean Coulthard. As a composer he wrote symphonies and other works for full or string orchestra, for string quartet, solo voice, chamber orchestra with winds, as well as voices.
He died in London.