Nico

"And with The Velvets come the blonde, bland, beautiful Nico, another cooler Dietrich for another cooler generation. Art [...] will never be the same again."

—John Wilcock of The East Village Other's review of the Exploding Plastic Inevitable show, quoted in the liner notes of The Velvet Underground & Nico CD.

Nico was a German singer, model, actress, and Warhol Superstar. Born in 1938, she started modeling when she was a teenager and later moved into acting, landing a minor blink-and-you-miss-it appearance in Fellini's La Dolce Vita. Later still, she started working with Andy Warhol and Paul Morrissey on their experimental films, and it was Andy who inserted her into the The Velvet Underground's lineup. The collaboration ended rather quickly because she and the band didn't really get along and the Velvets soon broke their ties with Warhol. Nevertheless, her work with the Velvets became legendary in the rock community, despite the fact that her involvement was limited: she only sang 3 songs and added backing vocals to another on The Velvet Underground & Nico. Additionally, she received no writing credits and was credited as "chanteuse".

Nico soon embarked on a solo career, using the opportunity to demonstrate the full range of her musical talent. Her debut album, Chelsea Girl, was met with praise, despite the fact that Nico wasn’t really involved in the production of the album and was dissatisfied with it. She started taking control of her music starting with her second album. Because of this, her sound evolved into something more experimental and harmonium-driven.

On July 18, 1988, Nico had a minor heart attack while riding a bicycle in Ibiza and hit her head as she fell. A passing taxi driver found her and had a hard time finding a hospital that would admit her. She was incorrectly diagnosed as suffering from heat-exposure instead of having a severe cerebral hemorrhage, and died as a result. Her legacy still lives on, as part of the Velvets and as a respected solo artist. Musicians influenced by her include Siouxsie and the Banshees, Bat for Lashes, Patrick Wolf, Bjork, Bauhaus, Coil, Elliott Smith, and Dead Can Dance. Also, despite their Creative Differences, the Velvets liked her voice enough that whenever they performed "I'll Be Your Mirror" (a song where they fought with Nico to get the final result) live, they'd sing it in a German accent.

Discography:

Chelsea Girl (1967)
The Marble Index (1969)
Desertshore (1970)
The End… (1974)
Drama of Exile (1981)
Camera Obscura (1985)

Nico provides examples of the following tropes:

Cover Version - "The End" by The Doors on the album of the same name, "I'm Not Saying" by Gordon Lightfoot as her first single, "I'm Waiting for the Man" by The Velvet Underground and "'Heroes'" by David Bowie on Drama of Exile, and the pop standard "My Funny Valentine" on Camera Obscura. In a variation, some of the songs for Chelsea Girl were written specifically for her by her collaborators.
Creator Backlash – see Executive Meddling.
Creator Breakdown – Nico wrote "You Forget to Answer" after she failed to reach ex-lover Jim Morrison by phone only to later find out that he had died.
Creepy Monotone
Darker and Edgier – The Marble Index is a hell of a shift from Chelsea Girl.
Doing It for the Art – Despite her talent as a singer-songwriter/musician, Nico was deaf in one ear.
Dream Team/Hey, It's That Guy! - Nico was good at getting help from talented musicians on her albums. For starters, her first single "I'm Not Sayin'"/"The Last Mile" was produced and had guitar by Jimmy Page. Chelsea Girls features her old VU mates Lou Reed, John Cale and Sterling Morrison along with Jackson Browne. The Marble Index and Desertshore had instrumentation entirely by Nico and Cale, The End kept Cale and added Roxy Music alumni Brian Eno and Phil Manzanera, Drama of Exile featured Ian Dury and The Blockheads saxophonist Davey Payne and David Bowie's keyboardist Andy Clark.
Early Installment Weirdness: Her first single, "I'm Not Saying"/"The Last Mile", is an unusually sunny affair compared to the Gothic gloom of her later works.
Epic Rocking - "It Was a Pleasure Then", the cover of "The End", "Fearfully in Danger".
Executive Meddling – Nico had little say in how Chelsea Girl was produced. This lead to her to disliking the album.

Nico: "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."

Harmony - From The Marble Index onwards, Nico wrote and recorded her songs on an Indian harmonium, which is tuned to an entirely different scale than the Western instruments that make up the rest of the music. The effect can be...
Kids Rock - "Le Petit Chevalier" from Desertshore is a 1 minute tune of Nico playing the harpsichord and her son Ari singing a few lines.
Lighter and Softer - The more New Wave influenced Drama of Exile coming right after the HONF-concentrated The End...
Magnum Opus – Chelsea Girl, although The Marble Index was probably her most influential album.
Neoclassical Punk Zydeco Rockabilly – Throughout Nico’s career, she has touched Baroque Pop, proto-goth, Synth Pop, folk, classical, rock, experimental, and New Wave.
New Sound Album – All of them!
One-Scene Wonder - Her work on The Velvet Underground & Nico: vocals on "Femme Fatale", "All Tomorrow's Parties" and "I'll Be Your Mirror". She was supposed to sing "Sunday Morning" as well but Lou Reed decided to take over at the last minute; you can still hear her backing vocals in the last minute of the track if you turn up the volume and pay attention.
Perishing Alt Rock Voice - Yeah, she and pretty much everybody else in VU. Except maybe Mo Tucker.
The Rashomon - Try to get a straight story of why there are two versions of Drama of Exile. The Other Wiki has more details.
Revival by Commercialization - "These Days" after it was in The Royal Tenenbaums. The K-Mart commercial didn't hurt either. Jackson Browne, the song's writer and guitarist, had to re-learn it before he could start playing it live again when people started requesting to hear it.
Rouge Angles of Satin - It's "You Forget To Answer", not "You Forgot To Answer".
Stage Names - Christa Päffgen was named "Nico" by Herbert Tobias, after his ex-boyfriend Nico Papatakis.