Question: Dan Wilson and Bert McCracken, have which mutual occupations?

Context paragraphs:
Shallow Believer: Shallow Believer is a compilation album by American rock band The Used that was released digitally on February 19, 2008.  The album is a compilation of b-sides from their first 3 studio albums.  The artwork was done by Bert McCracken and Alex Pardee.  It gets its title from a lyric in the song "Slit Your Own Throat".  On Record Store Day (April 18, 2015) the compilation received a physical release on royal blue vinyl, limited to 3,000 copies.

Cornish Cowboy: Based out of his ramshackled farm in Bodmin, Cornwall, England, Dan Wilson is a horse trainer, commonly referred to as a 'horse whisperer'.  Using his remarkable techniques, Dan breaks in and trains horses where other trainers have tried and failed.

All That I've Got (The Used song): "All That I've Got" is a song by American rock band The Used.  It was released in December 2004 as the second single from their second studio album, "In Love and Death".  "All That I've Got" was dedicated to Bert McCracken's dog, David Bowie, who was hit by a truck during the making of the album.  An acoustic version was later released on iTunes.  It was used in the "Saints Row 2" soundtrack.

Bert McCracken: Robert Edward "Bert" McCracken (born February 25, 1982) is the lead singer and songwriter of the American rock band The Used.

The Used: The Used is an American rock band formed in Orem, Utah, in 2001.  The group consists of vocalist Bert McCracken, guitarist Justin Shekoski, bassist Jeph Howard, and drummer Dan Whitesides.

Dan Wilson (musician): Daniel Dodd "Dan" Wilson (born May 20, 1961) is a singer, songwriter, musician, producer, and visual artist.  His songwriting resume includes "Closing Time", which he wrote for his band, Semisonic, "Not Ready to Make Nice" (co-written with the Dixie Chicks) and "Someone like You" (co-written with Adele).  He earned a Grammy nomination for “Closing Time” (Best Rock Song) and won Grammys for Song of the Year (“Not Ready to Make Nice” in 2007) and Album of the Year (which he won in 2012 as one of the producers of Adele’s "21").

In Love and Death: In Love and Death is the second studio album by American rock band The Used.  It was released on September 28, 2004 and was later certified gold in the United States, indicating over 500,000 copies shipped.  It is their most commercially successful album to date.  The title and music reference a number of tragic events that surrounded vocalist Bert McCracken during the album's production, notably the death of his pregnant girlfriend.  "In Love and Death" is the final studio album to feature drummer Branden Steineckert.

Someone like You (Adele song): "Someone like You" is a song by British singer Adele.  It was written by Adele and Dan Wilson for her second studio album, "21".  It is the second single and final track on the album.  The song was inspired by a broken relationship, and lyrically speaks of Adele's coming to terms with it.  XL Recordings released the song as the second single from the album on 24 January 2011 in the United Kingdom and on 9 August 2011 in the United States.  Accompanied only by a piano in the song (played by co-writer Wilson), Adele sings about the end of the relationship with her ex-boyfriend.  The song received wide acclaim from music critics, who chose the song as a highlight of "21" and praised the lyrics, its simple sound and Adele's vocal performance.

Dan Brenner: Dan Brenner (born Daniel Abraham Brenner, December 19, 1963) is an American songwriter, composer, and musician.  Brenner was a member of the band Magnet, with Moe Tucker (former drummer in the Velvet Underground) in the late 1990s, and of the rap/performance-art band Razor Magnet with his brother, filmmaker Evan Brenner from 1985-1988.  He was a member of the Boston bands Green Fuse and Gunga Din in the early 1990s, and prior to that, while a student at Harvard College, The Love Monsters, with brothers Matt Wilson and Dan Wilson, who later formed the Minneapolis bands Trip Shakespeare and Semisonic.  Brenner has written the scores for three feature films, including Rhythm Thief (Special Jury Prize at Sundance, 1995), Spare Me ("Priz Tournage" winner Avignon Film Festival, 1993), and The Riddle (a.k.a. Sasha’s Riddle, winner Long Island Film Festival, 2010, official selection Toronto Film Festival 1997).  Brenner also co-wrote the script for The Riddle, for which he was awarded the 2010 Mario Puzo Screenplay Award.  Some of Brenner's film composition is credited as "Danny Brenner," while some of his acting work is credited as "Daniel Brenner."  He is credited as Producer on the Foggy Notion CD Mission.

Pretty Handsome Awkward: "Pretty Handsome Awkward" is the second single from The Used's third studio album, "Lies for the Liars".  The song impacted radio on August 21, 2007.  It is also featured on the as well as a downloadable track on "".  The single peaked at No. 37 on the U.S. Hot Modern Rock Tracks.  It was rumored that the track was written about My Chemical Romance frontman Gerard Way, but Bert McCracken said that this is not true.

Supporting paragraphs: Dan Wilson (musician) Bert McCracken
Answer: singer and songwriter