|Weegee (Arthur Fellig), American, born Austria. 1899–1968, Coney Island. c. 1939, Gelatin silver print, 10 5/16 x 13 11/16″ The Museum of Modern Art.|
If you're as compulsive as I am, get there just before 9:30, wait at the eastern-most door on the 54th Street entrance (it's the first to open) and make a beeline to the elevator to the sixth floor. You'll have the exhibition pretty much to yourself for about 20 minutes, and if you stay a gallery ahead of the crowd, you can have it pretty much to yourself for the whole hour.
If you're not a member, or don't know a member to go with, your choices are pretty limited. Your best bet is to purchase timed tickets ($20!) online here. Admission is free Friday nights from 4:00 to 8:00 p.m., and a limited number of timed tickets to the Matisse exhibition are available on a first-come, first-served basis. But whether you paid $20 online or are lucky enough to score a free ticket on a Friday night, the show will be very crowded.