I've always felt Jon Boden's singing style was in parenthesis, a manner of address his audience is supposed to 'get', a way through the minefield of talking one way and performing a different one entirely. There's a difference between singing under a flag of convenience and opting for default Mummerset through galloping bucholia and imagination deficit.

In the same way a band like Dr Feelgood always sounded Canvey Island even when Lee Brilleaux was adopting the mores of Mississippi, more so in fact. Likewise Mick Jagger's art school camp is underlined by his cod   blues. So long as singer and audience know what's up there's no harm done.