Does anybody remember Al Jolson?

Absolutely. His act wouldnt pass the sensitive test nowadays. He frequently wore what they called "blackface". and sang songs that sounded somewhat *****. See,things have gotten so bad now that I'll probably get kicked out of YA for using word *****.

II love Al Jolson. I have the Jazz Singer on DVD, it comes with numerous Vitaphone shorts. I also have Hallelujah, I'm a Bum which also stars Harry Langdon. I am glad to see Al Jolson mentioned here. I wish some of his other films were on DVD. I have an Eddie Cantor DVD with a clip of Cantor speaking about Jolson after his death and Cantor's son does a pretty good impersonation.

he was an entertainer in the old days he dressed up in black make-up and sang songs like Mammy

Yes, he did routines in vaudeville dressed in "black face". His most famous song was "Mammy".

Who?

Wasn't he the signer that performed in black face? God Bless.