Question: Stellar West and Sum 41 are both what?
Context: Stellar West is an American rock band from Naperville, Illinois formed in 2014.  The group consists of Parker Belonio (vocals, guitar), Cole Onley (bass guitar), and Jake Deutschman (drums).  Their debut release, the EP "Songs From the Basement", was released October 22, 2015 and their first album, "Unfiltered", was released November 13, 2016.  Both the EP and LP were produced by Adam Krier and engineered by Andy Gerber at Million Yen Studios.  Pre-production was done at Sound Summit with Adam Krier and Charlie Dresser. "Underclass Hero" is the first single from Sum 41's fourth studio album "Underclass Hero".  The song impacted radio on May 15, 2007.  The song in its entirety was leaked on April 23 from a 91X podcast interview with Deryck Whibley.  It was confirmed on Sum 41's official site that this would be the opening track for the album.  The song was used in the EA Sports computer game "Madden 08" and Sony's "NBA 08".  It is the band's first single since the departure of guitarist Dave Baksh. Sum 41 is a Canadian rock band from Ajax, Ontario.  Originally called Kaspir, the band formed in 1996 and currently consists of lead vocalist/rhythm guitarist/keyboardist Deryck Whibley, lead guitarist/backing vocalist Dave Baksh, rhythm/lead guitarist/keyboardist/backing vocalist Tom Thacker, bassist/backing vocalist Jason McCaslin and drummer Frank Zummo. All the Good Shit: 14 Solid Gold Hits 2000-2008 (known as 8 Years of Blood, Sake and Tears: The Best of Sum 41 2000-2008 in Japan due to controversy at the time) is a greatest hits album by Sum 41.  The Japanese version was released on November 26, 2008, and the worldwide version was released on March 17, 2009.  This is the band's first greatest hits album.  It includes singles from each of the band's studio albums, as well as a previously unreleased song, "Always".  The release also includes a bonus DVD with all of the band's music videos (excluding "Some Say" and "Handle This").  At some stores, the title of the album was censored as "All the Good Stuff" or "All the Good Hits", although the lyrics remained explicit.  On some versions of the album the title "Makes No Difference (Alternate Version)" is misspelled as "Makes No Difference (Alternate Version)". Rocked: Sum 41 in Congo is a 2005 film documentary directed by Adrian Callender describing the experiences of Sum 41 joining War Child Canada in traveling to the Democratic Republic of the Congo (DRC).  Eric Hoskins, President of War Child Canada at the time, and Samantha Nutt, Executive Director of War Child Canada, accompanied Sum 41 to DRC in May 2004 and are credited as Executive Producers. Canadian peacekeeper Chuck Pelletier helped Sum 41 evacuate from DRC.  He is the namesake of the band's October 2004 album, "Chuck". The Don't Call It a Sum-Back is a concert tour by Canadian pop punk band Sum 41.  The tour, announced on August 8, 2016, will start October 5 and conclude on November 6.  The tour will support Sum 41's sixth studio album, "13 Voices".  In March 2016, the band announced that they will play in Warped Tour 2016.  The post-hardcore band Senses Fail and British pop punk band As It Is will perform as well.  On October 10 they announced UK dates starting on February 24 at Birmingham O2 Academy and finishing October 6 at Southampton O2 Guildhall. Jason Paul "Cone" McCaslin (born September 3, 1980) is a Canadian musician.  He is the bassist and backing vocalist of the band Sum 41.  He joined the band in November 1998.  Sum 41 was signed by Island Records in December 1999. "No Reason" is the fourth single and second track by the Canadian rock band Sum 41, from their fourth studio album "Chuck" (2004).  It was released in the United States and Europe as a promotional single.  The song is the main track of the soundtrack of the movie "Dirty Love".  Before the movie's premiere, Sum 41 released an unofficial music video for the single as a promotion for the movie, showing the band's scene in the movie where they play live, along with various other scenes from the movie.  It was the band's last single before the departure of Dave Baksh in May 2006. Thomas Arnold "Tom" Thacker (born April 11, 1974) is the lead guitarist, lead singer and co-founder for Canadian punk rock group Gob, as well as a producer.  He is also one of the guitarists in the band Sum 41.  Thacker formed Gob with Theo Goutzinakis in 1993.  After already being a touring member of Sum 41 since 2006, Thacker became the lead guitarist, keyboardist and backing vocalist for the band in 2009 and is currently serving as both the co-rhythm and co-lead guitarist since Dave Baksh returned to the band in 2015. David Nizam "Brownsound" Baksh is a Canadian musician, singer and producer best known as one of the lead guitarists of rock band Sum 41.  Baksh left the band for nine years, but returned in 2015.  After leaving Sum 41, he became a singer and guitarist in his own heavy metal/reggae project Brown Brigade.  He also plays guitar for Organ Thieves, with two of his fellow Brown Brigade members and the Canadian death punk four-piece Black Cat Attack.
Answer: rock band