Found the document from 2014 about
'CAMUS Musicians Dress' and at that time "
the Band of the Brigade of Gurkhas was not part of CAMUS" , whether that changed between then and now I don't know.
There is an afternote:
"As musicians in No 2 Dress in the Band of the Brigade of Gurkhas have a number of very easily distinguishable features, there can be no confusion with
musicians from any other Bands. Col BG therefore agreed that there was no necessity to wear a shoulder flash which in any case would be in addition to their existing metal Shoulder Title of “Gurkha”.
https://assets.publishing.service.go...ns-ADC-351.pdf