Seriously - there were some white men singing blues, such as Dick Justice and Frank Hutchison, around 1930. As to Can Blue Men Sing the Whites ...
1) I was lying in my bed, pulled the silken sheets up tight,
I gotta keep my strength, I've gotta do a show tonight.
I have a sip of coffee while I'm taking in the news,
Don't need to have a shave because I've got to sing the blues
CH) Woo - oo ee, woo - oo ee, woo ee
Can Blue Men Sing the Whites, or are they hypocrytes
For singing Woo oo ee woo ee
2) can't remember except
... I light a big cigar
Because I like to look like Nimrod when I'm riding in my car
3) And now it's getting near the time I've gotta make the scene
I take off my dark grey mohair suit, put on my dirty jeans
the band comes round to pick me up, I holler "Hello boys"
I've got to let my hair down if I'm gonna make some noise
closely related to the Fleetwood Mac Chicken Shack John Mayall Can't Fail Blues, recorded by the Liverpool Scene, aka the Jethro Tull Bellyful Savoy Brown Reach Me Down Blues