Following undergraduate study at St Johnís (where he read Classics), Rootham studied at the Royal College of Music. He succeeded Walford Davies as Organist of Christ Church, Hampstead, in 1898. In 1901 Rootham became Organist of St Asaph Cathedral, returning to St Johnís in the same year; he subsequently became University Lecturer in Music, and was made a Fellow in 1914. Rootham worked closely with the Cambridge University Musical Society in the promotion of contemporary music, leading performances of works by KodŠly, Honneger and Pizzetti. Although he composed widely, Rootham is remembered for his encouragement of contemporary composers, as well as the revival of forgotten works by Handel and Mozart.