We are such a diverse crowd that we need more than one term.

Muckle Mudcateers
A Gargle of Yodellers
A Coppice of Carol Singers
A cargo of Shanty Singers
A Remuda of Country Singers
A Bar of blues singers
A Paucity if Pipers (wishful thinking here)
An Archive of Old Fogeys
and I suppose that a collection of Art's fans could be called 'A Muse'

Bert.