Is it possible to volunteer for deployment / transfer corps/regiments?
It is possible but not guaranteed. Your desire to do your bit is admirable and it would be something that you would need to discuss with your chain of command on completeion of your training. It is not beyond the realms of possiblity EDIT: Just to keep AL G up to speed on things, Bandsmen now join a single corps CAMUS, the Corps of Army Musicians. From here they are now posted between regimental and divisional bands as easy as it for someone to move squadrons in any other corps. There is a recent article in Soldier magazine about a Corporal who is a musician who is currently doing a two years tour at an ATR as a instructor, so anything is possible!