I suppose we could add the folky part of his biog to Mudcat :
" In May/06 and again in August/06 Brigham went to Moscow to play and record his arrangements with the Moscow Festival Orchestra for Somerset Entertainment, which resulted in two CDs,
Celtic Isles
(celtic classics with full orchestra) and
Napa Valley
(classics of the American songbook).

Most recently he produced Celtic Roses for Somerset, a cd of celtic songs featuring four different singers.

– From 2006 -2011 Brigham arranged many CDs for Somerset Entertainment, mostly of a Celtic nature –

Celtic Wedding –
When Irish Eyes Are Smiling –
Celtic Serenity –
A Pint of Ale –
Celtic Christmas –
Heart of Ireland
... and others.*

– He has arranged dozens of songs for John McDermott for full orchestra, heard on John’s PBS TV special A Time to Remember (2002) and on John’s CD Remembrance featuring the Vancouver Symphony Orchestra.

– His production and arrangements on the debut CD by the Cape Breton traditional group The Cottars
led to their receiving the Best New Artist award at the 2003 East Coast Music Awards."

*according to Spotify(not too reliable)
He used the name Carlyle Fraser
on nine albums?
Celtic Wedding
Celtic Serenity ?
Celtic Spa 
Celtic Christmas
Celtic Angels
Celtic Beauty
Charme Celtique 
Heart Of Ireland
Pint Of Ale

He used his own name Brigham Phillips on
At The Pub - A Celtic Celebration
When Irish Eyes Are Smiling
Irish Celebration
Celtic Isles : A Romantic Journey
The Celtic Romance Collection

but I think there are at least two male voices amongst the tracks I happened to play.
He doesn't claim anywhere in his biog that he actually sings?