Some of her accompanists wrote songs for her to sing, and these form the backbone of Chelsea Girl. Browne and Hardin contributed some songs, "Wrap Your Troubles in Dreams" by Lou Reed was part of the earliest Velvet Underground repertoire (which did not surface as a Velvet Underground recording until it was included in the 1995 box setPeel Slowly and See), and Reed, Cale and Morrison in various combinations contributed four more songs. Additionally, Bob Dylan gave her one of his songs to record: "I'll Keep It with Mine".
Musically, Chelsea Girl can be described as a cross between chamber folk and 1960s pop. The musical backing is relatively simple, consisting of one or two guitars or, alternatively, a keyboard instrument, played by either Browne or (a combination of) her Velvet Underground colleagues. There are no drums or bass instruments. Adding to the chamber folk feel of the music is the strings and flute arrangement superimposed over the initial recordings by producerTom Wilson and arranger Larry Fallon without involving or consulting Nico.
Nico was dissatisfied with the finished product. Looking back in 1981, she stated:
I still cannot listen to it, because everything I wanted for that record, they took it away. I asked for drums, they said no. I asked for more guitars, they said no. And I asked for simplicity, and they covered it in flutes! [...] They added strings and – I didn't like them, but I could live with them. But the flute! The first time I heard the album, I cried and it was all because of the flute.