In 1962, Alldis founded the professional, 16-member John Alldis Choir, which launched itself with the world premiere of Alexander Goehr's A Little Cantata of Proverbs. Contemporary music figured importantly in its repertory, with first performances of works by Malcolm Williamson, Richard Rodney Bennett and Harrison Birtwistle, many of which were captured on the Argo label. In 1967, he prepared the John Alldis Choir for the first European performance of Stravinsky's Requiem Canticles, conducted by Pierre Boulez. The choir's 1972 recording of Justin Connolly's Verse, Op. 7b, was re-released in 2008 on the Lyrita label. The choir also participated in many opera recordings for Decca and RCA, featuring artists such as Luciano Pavarotti, Plácido Domingo, Janet Baker, Joan Sutherland and Kiri Te Kanawa.