The band was formed in 1997 by original members Gunnar Örn Tynes and Örvar Þóreyjarson Smárason, who were joined a year later by twin sisters Gyða and Kristín Anna Valtýsdóttir. According to Kristín, the band's name was not intended to mean anything. In 2002, after the first American tour, Gyða left the band to return to her studies in Reykjavík. Shortly after Gyða left, Ásthildur Valtýsdóttir joined for singing duties and Serena Tideman replaced Gyða on cello, for a European tour. Then the ensemble evolved to include Ólöf Arnalds and Hildur Guðnadóttir. In early 2006, Kristín also left the band, although it was not officially announced until November 23 of that year.
Despite the departure of some of its members múm has remained together as a collective of musicians. Their fourth album, recorded during 2006, was released on 24th of September, 2007, entitled Go Go Smear the Poison Ivy.
In November 2007, múm toured the East Coast of the US with German musician, Hauschka. They returned in Spring 2008 with the same set list. Both tours included songs from their latest album, Go, Go Smear the Poison Ivy.
On August 27, 2008, múm announced on their official website that "múm is quietly but surely [working on] their new album. No release date has been etched in stone, but every day will bring it closer." múm also released several pictures of themselves during the recording process on their My Space page.
On May 22, 2009, during a concert in Burgos, Spain, múm played songs from their upcoming album Sing Along to Songs You Don't Know. It was released through Gogoyoko on August 17th, 2009, and will officially be released on August 24, 2009, but has already leaked online. .
- Yesterday Was Dramatic – Today Is OK (TMT, 2000; reissue Morr Music, 2005)
- Finally We Are No One (Fat Cat Records, 2002)
- Loksins erum við engin (Smekkleysa Records, 2002) — the Icelandic version of "Finally We Are No One"
- Summer Make Good (Fat Cat Records, 2004)
- Go Go Smear the Poison Ivy (Fat Cat Records, 2007)
- Sing Along to Songs You Don't Know (Morr Music, 2009)
- Blái Hnötturinn (2001) — Soundtrack
- Motorlab #2 (2001) — 3 tracks contributed to compilation album by Kitchen Motors
- Please Smile My Noise Bleed (Morr Music, 2001) — 3 New Tracks + Remixes
- Remixed (TMT, 2001) — Versions of Yesterday Was Dramatic - Today Is Ok
- Fálkar (Smekkleysa Records, 2002) — contributed "Grasi Vaxin Göng"
- Wicker Park (soundtrack) (Lakeshore Records, 2004) — contributed "We Have a Map of the Piano"
- Screaming Masterpiece (2005) — Appeared in the documentary with the video for "Green Grass of Tunnel" and contributed the same song to the soundtrack.
- Friends of the Random Summer (2005) — 3 CD, Unofficial Release.
- Kitchen Motors Family Album/Fjölskyldualbúm Tilraunaeldhússins (Spring 2006) — contributed "Asleep in a Hiding Place"
- The Ballað of the Broken Birdie Records (TMT, 2000)
- Dusk Log (Fat Cat Records, 2004)
- The Peel Session (Fat Cat Records, 2006) (Maida Vale 4 Studio 2002)
- "Green Grass of Tunnel" (Fat Cat Records, 2002)
- "Nightly Cares" (Fat Cat Records, 2004)
- "They Made Frogs Smoke 'til They Exploded" (Fat Cat Records, 2007)
- "Marmalade Fires" (Fat Cat Records, 2007)
Biography from Wikipedia