Normally there are eight of them, but tonight's show at The Brewdog in Birmingham is performed by a slimmed down version of the band, hammering through a few of their latest numbers before the crowd settles back to hear new album "A Life Unlimited" over the P.A.
As singer-guitarist Neil Jones gives it the full-on, neck bulging emote during "Pushing Your Love", the thought strikes you that these guys could easily earn a comfortable crust knocking out Motown covers for the wedding circuit - or maybe they could hustle a living as a Blues Brothers tribute act.
But that just wouldn't be good enough. Though clearly enamoured of the classic sounds of black America - not to mention a plentiful dash of Van Morrison and Dexy's - Stone Foundation are all about taking inspiration from the music they love, not merely copying it.
It's an approach which has won the backing of Northern Soul legend Nolan Porter - now a regular collaborator - and, on their latest release, Graham Parker - one of Britain's greatest white "black" voices.
Like so many thoroughly worthwhile bands, they suffer from the chronic lack of airplay on UK radio for musicians who aren't backed by oodles of record company payola and/or don't look like they would adorn your daughter's bedroom wall.
Yet they already have a following in Japan and must surely be close to something like a breakthrough here. You have to believe that songwriting and musicianship of this quality can't be ignored.
They're touring with the full complement in the autumn and should not be missed.
"A Life Unlimited Is Out Now".