Glen has a passion for Twentieth Century British film and concert music, having reconstructed orchestral and choral film music for commercial release in the UK, US and Japan.

Whilst a student he researched manuscripts held in the David O. Selznick Collection (part of the Harry Ransom Center at the University of Texas at Austin) – from Bernard Herrmann to Miklós Rózsa. Returning to the UK to complete his studies, Glen spent time with patrons – including composer James Bernard – and developed long-standing ties with estates including that of composer Benjamin Frankel, amongst others.