William Patrick Corgan Jr. (born March 17, 1967) is an American musician, songwriter, producer, poet, and professional wrestling magnate. He is best known as the lead singer, primary songwriter, guitarist, and sole permanent member of The Smashing Pumpkins. Formed by Corgan and guitarist James Iha in Chicago, Illinois, in 1988, the band quickly gained steam with the addition of bassist D'arcy Wretzky and drummer Jimmy Chamberlin. Strong album sales and large-scale tours propelled the band's increasing fame in the 1990s until their break-up in 2000.

Following a brief stint touring with New Order in the summer , Corgan reunited with Chamberlin to form the band Zwan with Corgan's old friend Matt Sweeney in late 2001. According to Neil Strauss of New York Times, during his few live performances with the band, Corgan says "is still a work in progress." The lineup was completed with guitarist David Pajo and bassist Paz Lenchantin. The band had two distinct incarnations, the primary approach being an upbeat rock band with a three-guitar-driven sound, the second, a folk and gospel inspired acoustic side with live strings. The quintet performed throughout 2002, and their debut album, Mary Star of the Sea, was released in early 2003 to generally positive reviews. In the midst of their supporting tour for the album, mounting conflict between Corgan and Chamberlin, and the other band members led to the cancellation of the rest of the tour as the band entered an apparent hiatus, formally announcing a breakup in September 2003.  In 2004 Corgan began writing revealing autobiographical posts on his website and his MySpace page, blaming Iha for the breakup of the Smashing Pumpkins, calling Wretzky "a mean spirited drug addict," and criticizing his former Zwan bandmates' fixation with "indie cred" and calling them "filthy", opportunistic, and selfish.  On September 17, 2003, Billy first presented his poetry at the Art Institute of Chicago's Rubloff Auditorium. In late 2004, Corgan published Blinking with Fists, a book of poetry. Despite mixed reviews, the book debuted on the New York Times Best Seller list. Around this time, he began posting autobiographical writings online under the title The Confessions of Billy Corgan.  Also in 2004, he began a solo music career, landing on an electronic/shoegaze/alternative rock sound for his first solo album, TheFutureEmbrace, co-produced and arranged by Bon Harris of Nitzer Ebb. Released on June 21, 2005, through Reprise Records, it garnered mixed reviews from the press and only sold 69,000 copies. Corgan toured behind his solo album with a touring band that included Linda Strawberry, Brian Liesegang and Matt Walker in 2005. This tour was not as extensive as previous Smashing Pumpkins or Zwan tours. Prior to recording TheFutureEmbrace, Corgan had recorded some 72 songs inspired by Chicago history for the largely acoustic ChicagoSongs project, which have yet to be released.

Answer the following question by taking a quote from the article: What is Zwan?
the band