Barack Obama's 60th birthday may have gotten scaled back from a bash to a small shindig ... but it's still about as star-studded as it gets.
Several celebs still on the guest list have been making their way to the summer garden party at the former president's $12 million Martha's Vineyard mansion to celebrate B.O. turning the big 6-0 ... including a pair of powerhouse couples -- John Legend and Chrissy Teigen, and Dwyane Wade and Gabrielle Union ... this according to the New York Times.
Don Cheadle's also arrived, and huge names like Jay-Z and Beyonce, Eddie Vedder, George Clooney and Steven Spielberg are all still expected to attend.
So who didn't make the scaled-down guest list? Many of Obama's former administration officials including David Axelrod, and many comedians like David Letterman, Conan O'Brien and Larry David ... giving the latter a fantastic idea for a future episode of "Curb Your Enthusiasm." Axelrod's the big surprise ... he engineered Obama's 2008 election victory.