I didn't ask but I'd guess he is a Private of the Coldstream Regiment of Foot Guards circa 1812.
I'll leave the link there as it will provide further information for those who want to discover more about army uniforms however I've been greatly assisted by Simon Huguet Link
who provided me with the following precise description:
This soldier re-enactor isn't a Guardsman after all. He is wearing the pre 1814 infantry of the line uniform with a 'stovepipe' shako. The white topped plume and the fluffy shoulder tufts on the epaulettes indicate he is a member of one of the centre companies as opposed to the 'light' or 'grenadier' companies. The clue to his Regt. is the number 94 painted on the flap of his knapsack which indicates he is a member of the 94th Foot. This was one of the few Regts that had no County name in the title [unlike for example the 28th Foot, The North Gloucestershire Regt.] This probably because prior to 1793 it was part of the famous 'Scot's Brigade' that was in Netherlands service so was not around when County affiliations were handed out.
The 94th Foot was disbanded in 1818 but reformed in 1823. It was subsequently linked in 1881 with the 88th Foot, the Connaught Regt. to become the 2nd Connaught Rangers, being finally disbanded in 1922.
Interestingly all the references I have found show the 94th as having green facings [the lining colour showing on collar, cuffs and turnbacks] whereas the re-enactor in the photo appears to have white turnbacks.
If he was a Coldstream guardsman he would have blue facings and would almost certainly have had the Royal cipher on his knapsack flap.
Other view: Link
The band: Link