Question: Matthew Sweet collaborated with the singer of what band formed in 1981? 

Context paragraphs:
The Bangles: The Bangles are an American pop rock band formed in Los Angeles in 1981.  They scored several hit singles as that decade continued.  The band's hits include "Walk Like an Egyptian", "Billboard" magazine's number-one single of 1987, as well as two number-two hits, "Manic Monday" and "Hazy Shade of Winter", and their 1989 number-one single "Eternal Flame".

Velvet Crush: Velvet Crush is an American power pop band from Providence, Rhode Island, United States, that achieved prominence in indie-rock circles in the early- and mid-1990s.  The band broke up in 1996 but re-formed in 1998 and have continued to record, releasing their most recent album in 2004.  Vocalist/bassist Paul Chastain and drummer Ric Menck are the band's core members, having previously worked together as Choo Choo Train, Bag-O-Shells, and The Springfields, and they share singing and songwriting duties.  Guitarist Jeffrey Borchardt (of Honeybunch) played on the band's first three albums, "In the Presence of Greatness", "Teenage Symphonies to God", and "Heavy Changes".  "In the Presence of Greatness" was produced by Matthew Sweet, while the second and third albums were produced by Mitch Easter.

Under the Covers, Vol. 1: Under the Covers, Vol.  1 is the first collaboration between alternative rock artist Matthew Sweet and Bangles singer Susanna Hoffs.  Released by Shout!  Factory in 2006, the album contains 15 cover versions of favorite songs from the 1960s and 1970s.  The album was a result of their mutual love for songwriting from the 1960s.  Matthew Sweet and Susanna Hoffs decided to record an album together in dedication of that era consisting of only cover versions.

A Fragile Tomorrow: A Fragile Tomorrow is an alternative/powerpop band from Charleston, South Carolina, formerly from Montgomery, New York.  The group formed in 2003 and included brothers Sean Kelly, Dom Kelly, and Brendan Kelly.  In 2006, bassist Shaun Rhoades joined the group.  The band has put out four studio albums, most recently the critically acclaimed "Make Me Over".  The band has shared the stage with/opened for Indigo Girls, The Bangles, Matthew Sweet, Toad the Wet Sprocket, Garrison Starr, Antigone Rising, K's Choice, Mac McCaughan of Superchunk, Drivin N Cryin, Continental Drifters, Blues Traveler, The Cowsills, Danielle Howle, Susan Cowsill, Amy Ray, and more.

The Thorns: The Thorns were an American acoustic rock band formed in 2002 as a project of Matthew Sweet, Pete Droge, and Shawn Mullins.

Albert Hammond Jr.: Albert Louis Hammond Jr. ("né" Hammond III; born April 9, 1980) is an American guitarist, singer, songwriter and music producer.  He is most famous for his role as rhythm and lead guitarist, as well as occasional keyboard player and backing vocalist, in the American rock band The Strokes.  He is the son of singer-songwriter Albert Hammond (best known for his 1972 hit single "It Never Rains in Southern California").  Hammond Jr. released his debut album "Yours To Keep" in 2006 and followed up with "¿Cómo Te Llama? " in 2008 and his EP, "AHJ" in 2013.  His third solo album, "Momentary Masters", was released through Vagrant Records on July 31, 2015.  The Beach Boys, Buddy Holly, Frank Black, Guided By Voices, John Lennon, Matthew Sweet and The Velvet Underground are often cited as his major influences.

The Pillowcase: The Pillowcase is a collaboration EP between alternative rock artist Matthew Sweet and Bangles singer Susanna Hoffs.  Released by Shout!  Factory in 2006 in collaboration with Parasol Records as a double-7" vinyl, it contains 4 cover versions of favorite songs from the 1960s.  It was designed as a companion piece to Sweet and Hoffs' album, Under the Covers, Vol.  1.  Two of the tracks on the EP appear on that album, while the other two tracks were exclusive to the EP.

Community Trolls: Community Trolls was the group name of a short-lived musical duo between Michael Stipe of R.E.M. and Matthew Sweet.  In 1983, they collaborated as part of the Athens, Georgia music scene, writing and recording three songs together.  One of the compositions, "Tainted Obligation", was nearly released on a compilation album in 1986, and later appeared on bootlegs; it was released officially in 2002.  Another Community Trolls' song, "Six Stock Answers", appeared in an unreleased indie film featuring Stipe, Sweet and some of their friends.

Mikel Erentxun: Mikel Erentxun (born 23 February 1965) is a Venezuelan-born Spanish rock musician of Basque heritage.  Formerly with the group Duncan Dhu, he started his solo career in 1992.  He has released six albums as a solo artist and has covered The Smiths' song, "There Is a Light That Never Goes Out", as "Esta luz nunca se apagará", as well as Morrissey's "Everyday Is Like Sunday" as "Todo es Igual Siempre".  He has collaborated with Mark Gardener, Robert Quine, drummer Pete Thomas, Lloyd Cole, Matthew Sweet and Fred Maher.  In 2005 the band the Lightning Seeds sued Erentxun for alleged plagiarism of their song "Pure", but it was finally dismissed.

Oh-OK: Oh-OK was an American musical group from Athens, Georgia formed in 1981 with singer/lyricist Linda Hopper, bassist/vocalist/lyricist Lynda Stipe, and drummer David Pierce.  Other members later included drummer David McNair and guitarist Matthew Sweet.  The trio began practicing together at parties in the college community in the spring of 1981.  Their first club performance break came when Stipe's brother, Michael Stipe of R.E.M., needed a backing band for a show at the 40 Watt Club.

Supporting paragraphs: The Pillowcase The Bangles
Answer: The Bangles