Bill Cosby's neighborhood filled up with cops on the same day the comedian turned 81.
Law enforcement sources tell us officers in Cheltenham, Pennsylvania received a call Thursday for loud music on Cosby's street. We're told about 4 units responded ... a couple in front of Cosby's home and some went around back.
Witness - Jazz - Music - Bill - Property
A witness tells us loud jazz music could be heard coming from Bill's property -- likely from a birthday party -- but once officers arrived, everything quieted down.