Question: Sammy Hagar and Pierre Bouvier, share which mutual occupations?

Context paragraphs:
Finish What Ya Started: "Finish What Ya Started" is a song by Van Halen taken from their 1988 album "OU812".  Despite the album being seemingly complete, Eddie Van Halen came up with the riff at 2 in the morning and went down to his then-neighbor Sammy Hagar to show it.  Hagar let Eddie in, and the two played guitars in his balcony until they had a completed song.  Once Eddie left, Hagar decided to write the lyrics despite being late at night.  The theme wound up being unfulfilled sex, summed up by Hagar as "blue balls.  In the song, Eddie Van Halen recorded his guitar part on a Fender Stratocaster plugged direct into the studio mixing console.  The song is one of only two Van Halen tracks featuring Sammy Hagar playing a rhythm guitar part, which he played on a Gibson acoustic.

Sammy Hagar (album): Sammy Hagar is Sammy Hagar's second solo album, released in 1977.  It is also often referred to as The Red Album, as it includes Hagar's first anthem, "Red", which is also the basis for his nickname "The Red Rocker".  Future multi-platinum selling producer Scott Mathews was talked into playing a drum solo on "Red" after being told Ringo Starr had played his only drum solo in the very same room on The Beatles' last album, named after the EMI Studios this album was recorded in, Abbey Road.

Sammy Hagar &amp; Friends: Sammy Hagar & Friends is a solo album by Sammy Hagar.  It is his twelfth solo studio album.  The album was released on September 24, 2013, by Frontiers Records.

Chuck Comeau: Charles-André "Chuck" Comeau {'1': ", '2': ", '3': ", '4': "} (born 17 September 1979) is a Canadian musician and drummer, best known for being the drummer of the rock band Simple Plan.  He also founded the apparel company Role Model Clothing along with his bandmate Pierre Bouvier and the band's best friend, Patrick Langlois.  He is also former drummer for the punk rock band Reset from 1993 to 1999, which he quit to form Simple Plan with his Reset bandmate who also left Reset, Pierre Bouvier.

A Fistful of Alice: A Fistful of Alice is a live album by Alice Cooper.  It was released in 1997, and was recorded the previous year at Sammy Hagar's Cabo Wabo club in Cabo San Lucas, Mexico.  Slash plays guitar for part of the album (returning the favor after Cooper guested on "The Garden from the 1991 Guns N' Roses album "Use Your Illusion I") and Cooper says before the song "Desperado" that it was written about Jim Morrison, who died in 1971, the same year Cooper wrote the song.  Also featured in the album are Rob Zombie on vocals and Sammy Hagar on guitar.  The last song, "Is Anyone Home?" , is a studio recording recorded specifically for the album.

The Best of Sammy Hagar (1999 album): The Best of Sammy Hagar is a Sammy Hagar compilation album.  The album's track listing incorrectly lists "Red" as a live track when it is, in fact, the studio version.

Pierre Bouvier: Pierre Charles Bouvier {'1': ", '2': ", '3': ", '4': "} (born 9 May 1979) is a Canadian singer, songwriter, musician, composer and actor who is best known as the lead singer and guitarist of the rock band Simple Plan.

The Best of Sammy Hagar (1992 album): The Best of Sammy Hagar is a Sammy Hagar compilation album.

Classic Masters (Sammy Hagar album): Classic Masters is a Sammy Hagar compilation album in the Classic Masters series.  The track listing is identical to "The Best of Sammy Hagar" albeit with 24-bit digital remastering.

Sammy Hagar: Samuel Roy Hagar (born October 13, 1947), also known as The Red Rocker, is an American rock vocalist, guitarist, songwriter, musician and entrepreneur.  Hagar came to prominence in the 1970s with the hard rock band Montrose.  He afterwards launched a successful solo career, scoring an enduring hit in 1984 with "I Can't Drive 55".  He enjoyed huge commercial success when he replaced David Lee Roth as the lead singer of Van Halen in 1985, but left the band in 1996.  He returned to the band for a 2-year reunion from 2003 to 2005.  On March 12, 2007, Hagar was inducted into the Rock and Roll Hall of Fame as a member of Van Halen.  His musical style primarily consists of hard rock and heavy metal.

Supporting paragraphs: Sammy Hagar Pierre Bouvier
Answer: singer, songwriter, musician