This song by Beck is playing in the background when Rory and Lane arrive at Madeline’s party and continues throughout the introductions to Madeline and Louise.
Where It’s At is from Beck’s acclaimed 1996 album Odelay, although he performed the song in concert earlier, including at Lollapalooza in 1995. The song went to #61 in the charts and #5 in the alternative music charts, earning Beck a Grammy Award for Best Male Rock Vocal Performance, while the music video won Best Male Video at the MTV Awards. The song uses samples from various sources, including one from a sex education album for teenagers – rather apt for Louise and Madeline’s later actions.
The cool alternative music at the party suggests they hired the same (rather implausible) DJ from the Chilton Winter Formal.