Mick Hartley

"Entertainers at South Side tavern. Chicago, Illinois":

[photo: Shorpy/Russell Lee for the Farm Security Administration]

Full size here. 

Looking at the comments at Shorpy (ordered earliest at the bottom), I see someone's suggested that the guitarist on the right could well be Lonnie Johnson – a suggestion that subsequent commentary would seem to confirm. 

Let's see now – who was that extraordinarily perceptive commenter?

Mick H? 

[An earlier post of mine on Lonnie Johnson is here. Unfortunately the main YouTube link there is no longer available, but this, from 1963, is good]