The highly improvisational "Sister Ray," which riffed on black leather, sunglasses, noise and more noise, was done in one take by the Velvet Underground, who agreed ahead of time that, good or bad, they would live with the results. While the recorded version was 17 minutes long, the band was known for stretching it to twice that length in a live setting. Andy Warhol didn't produce the song, but he did have input on "Sister Ray." According to Reed, "When we were making the second record, [Warhol] said, 'Now you gotta make sure that you do the 'sucking on my ding dong song.'"