Question: How many studio albums have been released by an American crossover thrash band from Los Angeles, California, formed in 1984 under the name The Brood, and influenced by an English heavy metal band formed in Leyton, East London, in 1975 by bassist and primary songwriter Steve Harris?

Context paragraphs:
Suicidal Tendencies: Suicidal Tendencies (also known as S.T. or simply Suicidal) are an American crossover thrash band founded in 1980 in Venice, California by vocalist Mike Muir, who is the only remaining original member of the band.  Along with D.R.I. and S.O.D., they are often credited as one of "the fathers of crossover thrash".  Their current lineup includes Muir, guitarists Dean Pleasants and Jeff Pogan, bassist Ra Díaz and drummer Dave Lombardo.  Notable former members of the band are lead guitarist Rocky George (now in Fishbone), rhythm guitarist Mike Clark (formerly of No Mercy, now in Waking the Dead), bassists Louiche Mayorga (now in Luicidal), Robert Trujillo (now in Metallica) and Stephen "Thundercat" Bruner, and drummers Amery Smith (later of Uncle Slam and the Beastie Boys), Jimmy DeGrasso (formerly or later of Y&T, White Lion, Alice Cooper and Megadeth, now in Ratt) and Brooks Wackerman (now in Avenged Sevenfold).

Join the Army: Join the Army is the second album by American crossover thrash band Suicidal Tendencies.  It was released in 1987 – four years after their self-titled debut album – and is one of the most well known albums for crossing over the genres of punk and thrash metal, known as crossover thrash, a genre that Suicidal Tendencies have been credited for creating.  "Join the Army" is arguably one of Suicidal Tendencies' popular efforts, although it only reached No. 100 on the "Billboard" 200 chart.  This was their first album with guitarist Rocky George and drummer R.J. Herrera, and their last recording with bassist Louiche Mayorga (although he did co-write songs on their next album "How Will I Laugh Tomorrow When I Can't Even Smile Today").  This is also the last album the band played hardcore punk.

D.R.I. discography: This is a discography of D.R.I., an American crossover thrash band formed in 1982 by Kurt Brecht, Spike Cassidy, Dennis Johnson and Eric Brecht.  D.R.I. currently consists of Kurt Brecht (lead vocals), Spike Cassidy (guitar and backing vocals), Harald Oimoen (bass), and Walter Ryan (drums).  The band rose to prominence in the US during the thrash metal era with their albums "4 of a Kind" and "Thrash Zone".  The band has released seven studio albums, two EPs (one of which is a split with Raw Power), one compilation album and two live albums.

Prong (band): Prong is an American crossover thrash band formed in 1986 by vocalist and guitarist Tommy Victor, the band's sole constant member.  To date, they have released twelve studio albums (including an album of song covers), one live album, four EPs, one DVD and one remix album.  Prong had two independent releases, "Primitive Origins" (1987) and "Force Fed" (1989), which attracted the attention of Epic Records, who signed the band in 1989.  Their first two albums on Epic — "Beg to Differ" (1990) and "Prove You Wrong" (1991) — were released to critical acclaim and garnered attention on MTV's "Headbangers Ball".  The band's 1994 album "Cleansing" was also very successful, and included one of their well-known songs "Snap Your Fingers, Snap Your Neck".  After releasing one more album ("Rude Awakening" in 1996), Prong disbanded in 1997, but reformed in 2002 and has continued to tour and record since then.

The Raven Age: The Raven Age is an English heavy metal band formed in London in 2009 by guitarists Dan Wright and George Harris (son of Iron Maiden bassist Steve Harris).  In 2014 the band recorded and released their self-titled EP before supporting Steve Harris British Lion and Tremonti on separate tours.  The band then supported Iron Maiden on The Book of Souls World Tour in 2016.  On 2 August 2016 the band announced their debut album "Darkness Will Rise" would be released in December 2016, but it ended up being released in March 2017.  The band supported Anthrax on the Among The Kings European Tour in 2017.

Uncle Slam: Uncle Slam was an American crossover thrash band from Los Angeles, California, formed in 1984 under the name The Brood.  They were influenced by punk rock bands of the 1980s like Suicidal Tendencies (which featured some of the members of Uncle Slam and The Brood), D.R.I., Corrosion of Conformity, Black Flag and the Circle Jerks, as well as heavy metal bands like Black Sabbath, Iron Maiden, Slayer and Motörhead.  Many of their songs are about politics, rebel themes, death, pain and violence.  Uncle Slam has released four studio albums (one was recorded under their original name) and four demo tapes (one was also recorded under their original name).  The band broke up in 1995 but in 2010 they reissued their 1988 album "Say Uncle" on CD for the first time.

Iron Maiden: Iron Maiden are an English heavy metal band formed in Leyton, East London, in 1975 by bassist and primary songwriter Steve Harris.  The band's discography has grown to thirty-eight albums, including sixteen studio albums, eleven live albums, four EPs, and seven compilations.

List of songs recorded by Iron Maiden: Iron Maiden are an English heavy metal band formed by bassist Steve Harris in 1975.  The band's first album, 1980's "Iron Maiden", was written primarily by Harris, with vocalist Paul Di'Anno co-writing two tracks and guitarist Dave Murray contributing "Charlotte the Harlot".  The 1981 follow-up, "Killers", was written almost entirely by the bassist, with frontman Di'Anno contributing only to the title track, "Killers" (the North American bonus track "Twilight Zone" was credited to Harris and Murray).  Bruce Dickinson replaced Di'Anno after the release of "Killers", although he did not contribute any songwriting to "The Number of the Beast", released in 1982, which featured three songs co-written by guitarist Adrian Smith.  "The Number of the Beast" also spawned Iron Maiden's first UK Singles Chart top ten in the form of "Run to the Hills", which charted at number seven on its release.  It was not until 1983's "Piece of Mind" that the songwriting process became a more varied and collaborative approach, with just four of its nine tracks being credited solely to Harris, two to Dickinson and Smith, one to Harris and Murray, one to Dickinson alone, and one to Harris, Dickinson, and Smith.  The Dickinson and Smith-penned "Flight of Icarus" was the first Iron Maiden single to chart in the United States, reaching number eight on the "Billboard" Mainstream Rock chart.

Stormtroopers of Death: Stormtroopers of Death (also known as S.O.D.) were an American crossover thrash band formed in New York City in 1985.  They are credited as being among the first bands to fuse hardcore punk with thrash metal into a style sometimes referred to as crossover thrash.  The band is also known for reuniting Anthrax members Scott Ian (guitars) and Charlie Benante (drums) with their former bassist Dan Lilker.  The song "Milano Mosh" from their 1985 debut album, "Speak English or Die", was the "Headbanger's Ball" intro anthem for many years.

Dave Murray (musician): David Michael "Dave" Murray (born 23 December 1956) is an English guitarist and songwriter best known as one of the earliest members of the British heavy metal band Iron Maiden.  Along with the group's bassist and primary songwriter Steve Harris, Murray has appeared on all of the band's releases.

Supporting paragraphs: Uncle Slam Iron Maiden
Answer: four