Thanks for that.

I've since found his military papers and it shows that he was in these regiments:

1916: 2/4 Batt. Norfolk Regt.
1918: 51st (Grad) Battn. The Notts & Derby Regt. - Regt. Number 202369
And I think it says something like 51st TRB or (G) Bn TR L & D Regiment - Not sure what that means. May be related to the Notts & Derby Regt.

Does anyone know of any good military band sites. It would be amazing, but unlikely, to find another photo he's in.