During their set yesterday at the 9:30 Club, Nick Zammuto, one half of The Books, introduced a song as being about the end of the world then changed his mind and said it was about conception. It was a good synopsis of the band’s music — it could be anything you want it to be.

The Brooklyn band’s songs are pastiches — mostly instrumental with guitar from Zammuto and electric cello from Paul de Jong, with found sounds, snippets of dialogue and the occasional percussion loop added. Not following traditional verse-chorus-verse structure, the songs are free-flowing and ambient, giving off a feeling rather than a meaning — some seemed to imbue a sense of awe about the world, aided by projected visuals, and others were more chaotic.

In concert, the duo sat on chairs below a video projection of sometimes abstract and sometimes spliced and edited clips from other videos. Even when Zammuto and de Jong were joined by a violinist and a guitarist (opener Todd Reynolds on violin and Zammuto’s brother on guitar), the audience naturally focuses on the video, which almost serves as an additional instrument. The videos are usually synced with the music, such as in the impressive “8 Frame” where every eight frames of video equaled a quarter note. And unlike other bands that show videos, such as Super Furry Animals or Caribou, the Books’ video is by design the most energetic performer — the musicians simply sit and make music.