JAY-Z is doing a 9/11 benefit in New York City on September 11th . . . the same day that his new album, “Blueprint 3″, hits stores.

It’ll take place at Madison Square Garden, and it’ll also be broadcast live on Fuse. The concert .called “Fuse Presents: Jay-Z Live from Madison Square Garden: Answer The Call” will begin at 9:00 P.M. Eastern.

It’ll raise money for the New York Police and Fire Widows’ and Children’s Benefit Fund . . . a charity for the families of rescue workers who died in the line of duty.