Question: Who was the name of the bassist featured on  the American rock band Weezers most successful studio album?

Context articles: Del Amitri discography
Avalon (Roxy Music album)
Weezer discography
My Music (album)
Pinkerton (album)
Dream Police
Images and Words
Escape (Journey album)
List of Black Sabbath band members
Toys in the Attic (album)

The discography of Del Amitri, a Scottish pop rock band formed in 1983, includes six studio albums, one live album, two compilation and 19 singles.
 Four of their studio albums reached the top 10 in the UK Albums Chart.
 Their first album, which is a self-title album released in May 1985 did not enter the UK Albums Chart at all, and their final studio album "Can You Do Me Good?
", released in 2002, peaked at number 13.
 The band's most successful studio album was their third "Change Everything", which reached second place in the UK Albums Chart.
 Also the band's compilation album, "Hatful of Rain: The Best of Del Amitri", got to fifth place in the UK Albums Chart.
 The band broke up in 2002.
 They played a reunion gig at The Hydro Glasgow on 24 January 2014.
 A live album, "Into the Mirror", recorded on the reunion tour in January and February 2014 was released on 20 October 2014.
Avalon is the eighth and final studio album by English rock band Roxy Music.
 Released in May 1982, it was recorded in 1981–82 at Compass Point Studios in Nassau, Bahamas, and is generally regarded as the culmination of the smoother, more adult-oriented sound of the band's later work.
 It was the band's most successful studio album, reaching No. 1 in the UK (for 3 weeks) and staying on the album charts for over a year.
 Although it only peaked at No. 53 in the United States, "Avalon" endured as a sleeper hit and became the band's only million-selling record in that country, ultimately receiving a RIAA platinum certification.
The discography of Weezer, an American rock band, consists of 10 studio albums, two compilation albums, one video album, six extended plays, twenty-eight singles and twenty-four music videos. Weezer's self-titled debut studio album, often referred to as "The Blue Album", was released in May 1994 through DGC Records.
 The album was a huge commercial success, peaking at number 16 on the US "Billboard" 200 and spawning the singles "Undone – The Sweater Song" and "Buddy Holly", both of which were responsible for launching Weezer into mainstream success with the aid of music videos directed by Spike Jonze.
 It has sold 3.3 million copies in the United States and has been certified triple platinum by the Recording Industry Association of America (RIAA), becoming the band's best selling album to date.
 Following the success of their debut album, Weezer took a break from touring for the Christmas holidays.
 Lead singer Rivers Cuomo began piecing together demo material for Weezer's second studio album.
 Cuomo's original concept for the album was a space-themed rock opera, "Songs from the Black Hole".
 Ultimately, the "Songs from the Black Hole" album concept was dropped; the band, however, continued to utilize songs from these sessions into work for their second studio album. "
Pinkerton" was released as the band's second studio album in September 1996.
 Peaking at number 19 on the "Billboard" 200, it was considered a critical and commercial failure at the time of its release, selling far less than its triple platinum predecessor.
 However, in the years following its release, it has seen much critical and commercial championing.
My Music is the third and most successful studio album by Bosnian alternative rock band Sikter.
 It was released on 21 August 2005 by Bosnian label Gramofon.
 Album was recorded from 2003 to 2005 at MML Studio in Sarajevo and mixed at MGKS Studio in Sarajevo 2005.
 Cover of album was made by bassist of the band Dragan Rokvić.
Pinkerton is the second studio album by American rock band Weezer, released on September 24, 1996 on DGC Records.
 After abandoning plans for a rock opera titled "Songs from the Black Hole", Weezer recorded "Pinkerton" between songwriter Rivers Cuomo's terms at Harvard University, where he wrote much of the album.
 It was the last Weezer album to feature bassist Matt Sharp.
Dream Police is the fourth studio album by American rock band Cheap Trick.
 It was released in 1979, and was their third release in a row produced by Tom Werman.
 It is the band's most commercially successful studio album, going to No. 6 on the "Billboard" 200 chart and being certified platinum within a few months of its release.
Images and Words is the second studio album by American progressive metal/rock band Dream Theater, released on July 7, 1992 through ATCO Records.
 It is the first Dream Theater release to feature James LaBrie on vocals.
 The album maintains its position as the band's most commercially successful studio album to date, and the song "Pull Me Under" has the distinction of being the only top-10 hit (radio or otherwise) the band has had to date.
 This particular song has also had more recent success as it has appeared in the 2008 video game "Guitar Hero World Tour".
Escape (stylized as E5C4P3 on the album cover) is the seventh studio album by American rock band Journey, released in 1981.
 It topped the American "Billboard" 200 chart and features four hit "Billboard" Hot 100 singles – "Don't Stop Believin'" (#9), "Who's Crying Now" (#4), "Still They Ride" (#19) and "Open Arms" (#2) – plus rock radio staple "Stone in Love."
 It was certified 9x platinum by the RIAA and sold over twelve million copies worldwide, making it the band's most successful studio album and second most successful album overall behind "Greatest Hits".
Black Sabbath were an English hard rock band from Aston, Birmingham.
 Formed in 1968, the group originally featured vocalist Ozzy Osbourne, guitarist Tony Iommi, bassist Geezer Butler and drummer Bill Ward.
 The initial lineup of the band lasted until 1977, during which time they released seven successful studio albums, including UK Albums Chart top-five releases "Paranoid", "Master of Reality" and "Sabbath Bloody Sabbath".
 Osbourne left the group in 1977 and was replaced briefly by Dave Walker, although the founding frontman returned the following year.
 His return was short-lived, however, and he was replaced in 1979 by Ronnie James Dio at the suggestion of Sharon Arden, who would later marry Osbourne.
 Butler also briefly left in 1979, although after hearing sessions recorded by replacement Craig Gruber he returned.
Toys in the Attic is the third studio album by American rock band Aerosmith, released on April 8, 1975 by Columbia Records.
 Its first single release, "Sweet Emotion", was released a month later on May 19 and "Walk This Way" was released on August 28 in the same year.
 The album is their most commercially successful studio LP in the US, with eight million copies sold, according to the RIAA.