Larry David -- The Birthday Street Rap

Everybody knows Larry David has a penchant for hip hop ... (see Krazee EyeZ Killa) ... which is probably why our photog decided to break out a personalized birthday rap for the "Curb" genius yesterday ... right in the middle of the street.

David -- who turned 65 years old yesterday -- was leaving a birthday dinner at Gjelina restaurant in Venice ... when our guy "treated" the TV icon to a couple of rhymes.