Big Sid to you.
The eBay seller says that the photograph came from the Burt Goldblatt collection. Goldblatt (1924-2006), whom we all know from album covers and famous photographs, was born in Dorchester, Massachusetts — so I am guessing that this photograph of Sidney (late in his short life) might have been taken in a Boston club — Sidney worked in that city in 1950, after leaving the Louis Armstrong All-Stars due to heart disease.
Perhaps this could be the soundtrack to this photograph:
Every little breeze — if it’s a rhythmic one — whispers “Sidney!”
This one’s for Romy, MB, KD, and Brother Hal . . .
May your happiness increase.