You seem to have a bizarre idea about traditional singers. Harry Cox didn't have a beard. Neither did Joe Heaney, Paddy Tunney, Walter Pardon, Jimmy McBeath, Sam Larner, Phoebe Smith, May Bradley or Elizabeth Cronin. On the other hand, Phil Tanner and George Maynard were suitably hirsute, although I'd be surprised if either of them were Guinness drinkers.

There may be a correlation between Irish traditional singers and Guinness, although Paddy Tunney was teetotal, but not between Irish traditional singers and beards - unless you count the Pecker Dunn, and I personally wouldn't.