Question: Adrián Barilari is the vocalist of the heavy metal band formed in what year?

Context paragraphs:
Volbeat: Volbeat are a Danish heavy metal band formed in Copenhagen in 2001.  They play a fusion of rock and roll, heavy metal and rockabilly.  They are inspired by classic rock and roll artists such as Elvis Presley and Johnny Cash, as well as modern hard rock, thrash metal, heavy metal, alternative rock and hardcore punk groups.  Their current line-up consists of vocalist and guitarist Michael Poulsen, guitarist Rob Caggiano, drummer Jon Larsen and bassist Kaspar Boye Larsen.  The band is signed to Dutch label Mascot Records and has released six studio albums and one DVD.  All of their studio albums have been certified gold in Denmark.  Their second album "Rock the Rebel/Metal the Devil" received platinum status, and their 2010 release "Beyond Hell/Above Heaven" was subject to widespread international critical acclaim, receiving double platinum in Denmark, platinum in Finland and Germany, and gold in the United States, Sweden and Austria.  Volbeat's sixth album entitled "Seal the Deal & Let's Boogie" was released worldwide on 3 June 2016.

Adrián Barilari: Adrián Eduardo Barilari (born November 11, 1959) is an Argentine singer best known as the vocalist of the heavy metal and hard rock band Rata Blanca.  He also has his own solo band.

Halford (band): Halford is an American heavy metal band formed in 1999 by British singer Rob Halford, who is best known as the lead vocalist for Judas Priest.  Halford formed the band to return to his heavy metal roots.  His two previous projects were a "street metal"-style band called Fight and the industrial metal band 2wo.

Biohazard (band): Biohazard is an American heavy metal band formed in Brooklyn, New York in 1987.  They are acknowledged as one of the earliest bands to fuse hardcore punk and heavy metal with elements of hip hop.  The earliest lineup consisted of bassist/vocalist Evan Seinfeld, guitarist Bobby Hambel, and drummer Anthony Meo.  Guitarist/vocalist Billy Graziadei would join the band soon after, changing the band to a four-piece.  Since February 2016, the lineup has consisted of Billy Graziadei, Bobby Hambel and Danny Schuler.

Acrassicauda: Acrassicauda is an American-based Iraqi heavy metal band formed in 2001.  It is often credited as being the first heavy metal group to emerge from Iraq.  The original band consisted of three Arab members and one Assyrian (Tony Aziz Yaqoo).  The band formed and played concerts under the regime of Saddam Hussein.  It became well known outside of the local Iraqi metal scene after Vice magazine did a profile of the band.  It received even greater coverage when it was profiled in a feature-length documentary about the band and its troubles in Iraq called "Heavy Metal in Baghdad".  The band's first album was released on March 9, 2010.

Sintax: Sintax is a thrash metal & heavy metal band formed in Jerusalem, Israel in 2010 as the band Shworchtsechaye disbanded.  Sintax is considered a super group in the Israeli metal scene.  The band has had many lineups throughout its inception as well as many variations in its style and musical approach fluctuating from punk, crossover and metal core influence into a heavy metal, NWOBHM, thrash and death metal sound, due to lineup change.

Rata Blanca: Rata Blanca (White Rat in English) is a heavy metal band from Argentina, formed in 1986.  It is considered the most famous metal band in its country, and one of the most important of the genre in South America.

El Libro Oculto: El Libro Oculto (The Hidden Book) is the fourth album by Argentine metal band Rata Blanca.  The album was recorded in 1993 in Spain.  The album has a heavier sound than previous albums.  After recording this album vocalist Adrián Barilari and keyboardist Hugo Bistolfi left the band.  Both Barilari and Bistolfi later founded Alianza.

Barilari: Barilari is a project band from Argentina fronted by the Rata Blanca vocalist Adrián Barilari.  The band formed in 2001 due to Adrian's wishes to form a solo project away from the demands of his other bands.  In 2003 he invited his friends from Nightwish and Jens Johansson from Stratovarius to become the makeup of this dream.  Barilari has been compared to such bands as Tobias Sammet's Avantasia and Ayreon.

Kekal: Kekal (sometimes stylized as KEKAL) is a heavy metal and electronic music band formed in 1995 in Jakarta, Indonesia.  According to AllMusic, Kekal was one of the first heavy metal bands from Indonesia to make international inroads, and according to sociologist of heavy metal, Keith Kahn-Harris, was one of the few extreme metal bands from Southeast Asia to ever make more than a minimal impression on the global scene.  Founded by two musicians known simply Yeris and Newbabe, the band underwent some shifts in lineup in its early years, but emerged with a consistent lineup of three key-members, guitarist/vocalist Jeff Arwadi, bassist Azhar Levi Sianturi, and guitarist Leo Setiawan.  Frequently labeled as black metal, progressive metal, and avant-garde metal, Kekal plays a very diverse range of music styles within the frame of metal and rock, incorporating many other music genres such as ambient, electronic, jazz fusion, and progressive rock.  Over the course of its career, Kekal has transitioned from a heavy metal-based style to a more experimental and electronic sound.

Supporting paragraphs: Adrián Barilari Rata Blanca
Answer: 1986