premise: Morley College Choir was founded by Gustav Holst, during the period he was teaching music at Morley College. The choir was led for many years by Michael Tippett, who conducted the ensemble for the first-ever recording of Thomas Tallis' Spem in Alium, and premiered a number of Tippett's works, including A Child of Our Time in March 1944.
hypothesis: Spem in Alium was not one of Tippett's works
reason: Spem of Alium was composed by Thomas Tallis and not by Michael Tippett