Question: Charlie Simpson and Pete Loeffler, have which mutual occupation?

Context paragraphs:
Well Enough Alone: "Well Enough Alone" is the first single from the Chevelle album "Vena Sera" and was released to radio the week of February 13, 2007.  According to lead singer Pete Loeffler, "Well Enough Alone" was an unreleased song that had been recorded prior to the release of their third album "This Type of Thinking (Could Do Us In)", before it was refined for "Vena Sera".

Chevelle (band): Chevelle is an American alternative metal band that formed in 1995 in the Chicago suburb of Wildwood, Illinois.  The band was originally composed of brothers: Pete Loeffler (lead vocals and guitar), Sam Loeffler (drums and percussion) and Joe Loeffler (bass and backing vocals).  When Joe left the band in 2005, Geno Lenardo subbed-in as the bassist until he was replaced by Pete and Sam's brother-in-law, Dean Bernardini.

When We Were Lions: When We Were Lions is the debut EP by Charlie Simpson, confirmed to be followed by his first solo full-length debut album in 2011.  In the live shows promoting Young Pilgrim he played 2 songs live from the EP which were 'If I Hide Will You Come Looking? '  and 'Farmer & His Gun' which is also a bonus track and is a live bonus track on the iTunes bonus tracks.  During his 'Young Pilgrim World Tour' he plays "When We Were Lions" and "Farmer & His Gun" as the encore.  Charlie announced in January that he is releasing a video for the track 'Bullet' from the EP despite being released 3 years prior, the single is just a one off.

Letter from a Thief: "Letter from a Thief" is the second single from Chevelle's album, "Sci-Fi Crimes".  It was released on December 7, 2009.  Chevelle originally debuted this track on April 9, 2009 at a concert in Atlanta.  Frontman Pete Loeffler said the song is about a personal experience for the band when their gear was stolen in Dallas, and his prized red PRS guitar seen in the video for "Send the Pain Below" was stolen, along with the rest of the band's gear, and returned by a man in California who returned the guitar to PRS after learning it was Loeffler's.

Propellers (band): Propellers are an indie rock/synthpop band from Royal Tunbridge Wells, Kent, England.  The band members are Max Davenport (lead vocals), Archie Davenport (guitar), Charlie Simpson (bass guitar), Jimmy Goodwin (keyboards) and Will Wilkinson (drums).

Pete Loeffler: Pete Loeffler (born October 19, 1976) is a musician, known for his work with the Chicago-area rock band Chevelle, for which he is the lead vocalist and sole guitar player.

Fightstar: Fightstar are a British rock band from London that formed in 2003.  The band is composed of lead vocalist, guitarist and keyboardist Charlie Simpson, guitarist and co-vocalist Alex Westaway, bassist Dan Haigh and drummer Omar Abidi.  Generally considered a post-hardcore band, Fightstar are known to incorporate metal, alternative rock and other genres into their sound.  During the band's early days, they were viewed sceptically by critics because of Simpson's former pop career with Busted.  Their live shows got a more positive reaction, and their 2005 debut EP, "They Liked You Better When You Were Dead", was a critical success.

Charlie Simpson: Charles Robert "Charlie" Simpson (born 7 June 1985) is an English singer, songwriter and musician.  He is the youngest member of multi-BRIT Award-winning band Busted, and is the lead vocalist, guitarist in post-hardcore band Fightstar.  AllMusic has noted that Simpson is "perhaps the only pop star to make the convincing transition from fresh-faced boy bander to authentic hard rock frontman".  Simpson is a multi-instrumentalist, playing guitar, keyboard, piano and drums.

Busted (band): Busted are an English pop rock band from Southend-on-Sea, Essex, consisting of James Bourne, Matt Willis and Charlie Simpson.  Formed in 2001, the band had four UK number-one singles, released two studio albums, "Busted" (2002) and "A Present for Everyone" (2003), one compilation album and one live album before breaking up in January 2005 following Simpson's decision to pursue a career fronting post-hardcore band Fightstar.  They have also won two Brit Awards and won The Record of the Year in 2004 with their single "Thunderbirds", amongst other awards.  Busted have sold over 5 million albums worldwide.

Down Down Down: "Down Down Down" is the debut single by English singer-songwriter Charlie Simpson, from his debut studio album "Young Pilgrim" (2011).  It was released on 11 April 2011 as a digital download in the United Kingdom.  The song peaked to the number 65 on the UK Singles Chart and number 9 on the UK Indie Chart.

Supporting paragraphs: Charlie Simpson Pete Loeffler
Answer: musician