The big deal this weekend in Brooklyn is Siren Fest (officially the Siren Music Festival) in Coney Island,
which the Village Voice has been producing since 2001. There are 14
bands on two stages; here's the schedule:

Main Stage (West 10th Street and The Boardwalk)

    1:00 Tiny Masters of Today
    2:00 Micachu & The Shapes
    3:00 Japandroids
    4:00 Frightened Rabbit
    5:00 Grand Duchy
    6:00 The Raveonettes
    7:30 Built To Spill

    DJ between sets: Justine D

Stillwell Stage (Stillwell Avenue and The Boardwalk)

    1:30 The Blue Van
    2:30 Bear Hands
    3:30 Thee Oh Sees
    4:30 Future of the Left
    5:30 A Place To Bury Strangers
    6:30 monotonix
    8:00 Spank Rock

    DJ between sets: Deadheat DJs

Although I haven't seen The Raveonettes live, I really liked their last
album (and just for the record, even though the Raveonettes' guitarist
and I have the same last name, we're not related).  And when I ran into
my high school classmate and music critic Billy Altman in Austin this
past March, he had just seen Brooklyn's Tiny Master of Today and was
quite enthused about them.

Siren Music Festival, Coney Island: D,F,N or Q Trains to Stillwell Avenue or F or Q Trains to W. 8th Street; 1-9 PM, Free

 –Eliot Wagner