Alwyn’s personal papers include a wide variety of material including pamphlets and brochures that cannot be included elsewhere eg travel brochures, address books, medical documents lists of first edition Victorian novels owned by Alwyn, and lists compiled by Doreen Carwithen of books by Alwyn’s bedside.

Also included here are the notebooks of John Blackwood McEwen, which were bequeathed to William following McEwen’s death. McEwen taught Alwyn composition at the Royal Academy, and became his friend and mentor. Indeed it was McEwen, who upon his appointment as Principal of the Royal Academy invited Alwyn to become a teacher of harmony and counterpoint at the college, McEwen’s former post. The notebooks principally consist of McEwen’s own lecture notes with the earliest notebook dating from ca. 1911, and the last from 1923. All the notebooks are holograph in ink or pencil.