Question: What are the names of the current members of  American heavy metal band who wrote the music for  Hurt Locker The Musical? 

Context paragraphs:
Joey Vera: Joseph "Joey" Vera (born April 24, 1963) is an American heavy metal bassist who is known as a member of the heavy metal band Armored Saint and the progressive metal band Fates Warning.  In 2004-2005 he replaced Frank Bello in Anthrax as the band's bassist, but did not record with them.  He was also a member of Engine, recorded with Tribe After Tribe, and appears on the OSI album "Free".  His first solo album, "A Thousand Faces", was released in 1994.  His current solo project, A Chinese Firedrill, released an album titled "Circles" in 2007.

Hurt Locker (musical): Hurt Locker The Musical is a fictional musical in the 2014 Broadway premiere production of "Hedwig and the Angry Inch".  In the Broadway performance of "Hedwig and the Angry Inch" the musical opens with Hedwig explaining that the musical only ran for a single night before closing during intermission, and that she has convinced a producer to let her perform in what would otherwise be an empty stage.  Fake Playbills for the musical are used as props and are found scattered on the floor of the Belasco Theatre and contains advertisements for other fake musicals based on feature films such as "Gravity on Ice", "Container Store: The Musical", "The Entire Bible", and "SoulCycle on Broadway".  The Playbills, which describe the musical as having "explosions, negligible storytelling, camouflage and tits", also state that the musical's cast included actors such as Taye Diggs (who would go on to play the role of Hedwig in the summer of 2015) and that the music was written by Metallica and Stephen R. Schwartz, which is the real name of "Hedwig" songwriter Stephen Trask.

Obús: Obús is a Spanish heavy metal band created in Madrid in the early 80s.  They stood out because they took the risk of making a big spectacle in their concerts in order to reach to the level of other international heavy metal bands.  In addition, the lyrics they write and the feelings they transmit connect with the people that follow them.  As they said in an interview: "All our songs , some more and some less, have a meaning".  Far away from renouncing to their genre, they have always claimed that they were a heavy metal band and they even wrote a song about this genre in their first LP called"Dosis de Heavy Metal". In 2012, because of their 30th anniversary, they did a Tour around Spain.

Metal Health: Metal Health is the third studio album by American heavy metal band Quiet Riot.  It was released on March 11, 1983, bolstered by the No. 5 hit "Cum On Feel the Noize" and the No. 31 hit "Metal Health".  "Metal Health" is notable for being the first heavy metal album to reach the top spot on the "Billboard" 200, replacing the Police's "Synchronicity" at number one in November 1983.  The album went on to sell more than six million copies and is considered a classic among heavy metal fans.  Some critics, such as AllMusic, describe it as a one-hit wonder, owing to Quiet Riot's relative lack of critical and commercial success with following albums (and subsequent disintegration) towards the end of the 1980s.  The title track was ranked No. 35 on VH1's 40 Greatest Metal Songs.

Joey Jordison: Nathan Jonas "Joey" Jordison (born April 26, 1975), is an American musician, songwriter, record producer and multi-instrumentalist, best known for his work as the former drummer and co-songwriter for the American heavy metal band Slipknot as well as guitarist in the American horror punk band Murderdolls.  Jordison played in Slipknot since their formation in 1995 until his departure from the band in December 2013.  He was the drummer and founder of the American heavy metal band Scar the Martyr which formed in 2013 and disbanded in 2016.  He grew up in Waukee, Iowa with his parents and two sisters, and was given his first drum kit at the age of 8.  He performed in several bands until joining in the summer of 1995 with the group The Pale Ones, which would later change their name to Slipknot.  Of Slipknot's nine-member lineup which lasted from 1999–2010, Joey was the third to join the band.

Black 'n Blue: Black 'N Blue is an American heavy metal band from Portland, Oregon.  The current members are singer Jaime St. James, bassist Patrick Young, drummer Pete Holmes, guitarist Bob Capka, and guitarist Brandon Cook.

Machine Head (band): Machine Head is an American heavy metal band from Oakland, California.  Formed on October 12, 1991, the group was founded by vocalist/guitarist Robb Flynn and bassist Adam Duce.  The current lineup of the band comprises Flynn, drummer Dave McClain, guitarist Phil Demmel and bassist Jared MacEachern.  Machine Head is one of the pioneering bands in the new wave of American heavy metal.

Dan Spitz: Daniel Alan Spitz (born January 28, 1963) is an American musician and watchmaker best known for his work as the lead guitarist, principal songwriter and co-producer of the American heavy metal band Anthrax from 1983 to 1995 and from 2005 to 2008.  With Anthrax, Spitz was nominated for three Grammy awards and has been awarded platinum and multiple platinum RIAA certified albums for his entire Anthrax catalog of work.  Dan Spitz is the first heavy metal songwriter to have his music playing on two planets.  NASA chose his song alongside only 9 other artists such as Frank Sinatra and the Beatles to be played on the Lunar Rover Curiosity making him the first heavy metal artist to have a top 10 charting song on two planets.  Spitz also founded the Christian music group Red Lamb alongside Dave Mustaine of Megadeth as his writing partner, the first to bring autism awareness into any genre of music or music video.

Nu metal: Nu metal (also known as nü-metal and aggro-metal ) is a form of alternative metal that combines elements of heavy metal music with elements of other music genres such as hip hop, alternative rock, funk and grunge.  Nu metal bands have drawn elements and influences from a variety of musical styles, including multiple genres of heavy metal.  Nu metal rarely features guitar solos; the genre is heavily syncopated and based on guitar riffs.  Many nu metal guitarists use seven-string guitars that are down-tuned to play a heavier sound.  DJs are occasionally featured in nu metal to provide instrumentation such as sampling, turntable scratching and electronic backgrounds.  Vocal styles in nu metal include singing, rapping, screaming and growling.  Nu metal is one of the key genres of the new wave of American heavy metal.

Metallica: Metallica is an American heavy metal band based in San Rafael, California.  The band was formed in 1981 in Los Angeles when vocalist/guitarist James Hetfield responded to an advertisement posted by drummer Lars Ulrich in a local newspaper.  Metallica's current lineup comprises founding members Hetfield and Ulrich, longtime lead guitarist Kirk Hammett, and bassist Robert Trujillo.  Guitarist Dave Mustaine (who went on to form Megadeth) and bassists Ron McGovney, Cliff Burton, and Jason Newsted are also former members of the band.

Supporting paragraphs: Hurt Locker (musical) Metallica
Answer: Hetfield and Ulrich, longtime lead guitarist Kirk Hammett, and bassist Robert Trujillo.