Underclass Hero is the fourth studio album by Canadian rock band Sum 41. It is the first of two albums by the band recorded without guitarist Dave "Brownsound" Baksh since he left a year earlier to focus on Brown Brigade. It was first released on July 18, 2007, in Japan by Island Records and distributed worldwide by Aquarius Records, the band's final album on the label. In comparison to the heavy metal-inspired punk style of their previous album Chuck (2004), Underclass Hero marked a return to the band’s pop-punk sound.

The album was a commercial success, peaking at number 1 on the Canadian Albums Chart and at number 7 on the US Billboard 200, becoming the band’s highest-charting album to date. It received generally mixed reviews from critics, with some praising its songwriting, lyrics and production, while others found it to be too long, melodramatic, and derivative.

Critics have consistently described Underclass Hero as a revival of Sum 41's previous pop punk style in All Killer No Filler (2001) as opposed to the heavy metal and punk rock sound found in Chuck (2004).^[1][2][3][4] However, the album differentiates itself from the band's early sound, through the incorporation of instruments such as acoustic guitars, pianos, organs and synthesizers, theatricality, emphasis on dark and political lyrics, dynamics and its disregard for metal influences, creating a sound more inline with the emo pop genre. Furthermore, songs such as "Ma Poubelle" combine this with elements of show tunes. PopMatters writer Ethan Stewart stated that "The way that Underclass Hero layers pianos, acoustic guitars, vocal harmonies, and ambient synthesizers easily makes it Sum 41’s prettiest-sounding record to date."^[5]

On April 16, 2007, Underclass Hero was announced for release. The next day, "March of the Dogs" was released as a promotional single.^[6] On May 2, 2007, the title track was posted on the band's Myspace profile; the music video for it was posted online at the end of the month.^[7][8] The album's artwork was posted online on June 8, 2007.^[9] On July 9, 2007, "Walking Disaster" was posted on Myspace.^[10] The album was made available for streaming on July 17, 2007 through MTV's website, and released through Island on July 24.^[6][11] On the same day, the band performed the album in its entirety, which was subsequently posted on their website.^[12] In August, the band played two shows in Australia with Yellowcard and performed at a few dates on the Warped Tour, alongside a few US shows with Yellowcard, Monty Are I and Amber Pacific the following month.^[13][14] On August 20, 2007, the music video for "Walking Disaster" premiered on MTV2's website.^[15] In September and October 2007, the band went on a tour of the US with Schoolyard Heroes, which included an appearance at the X96 Big Ass Show radio festival.^[16][17] In November 2007, the band announced that singer/rhythm guitarist Deryck Whibley was suffering from a herniated disc, resulting in all of the remaining shows of the year to be cancelled.^[18] In February and March 2008, the band toured the UK, which was followed by a stint in Canada; both were supported by Die Mannequin and Social Code.^[19] They toured Australia in April 2008 with Pennywise, the Vandals and Bowling for Soup.^[20]

All songs written and composed by Deryck Whibley, except where noted.

Sum 41

• Deryck Whibley – lead and backing vocals, guitars, keyboards, piano, producer
• Jason "Cone" McCaslin – bass, backing vocals
• Steve Jocz – drums

Additional musicians

• Jamie Muhoberac – keyboards
• Dan Chase – percussion
• Michael Railton – piano

Technical

• Doug McKean – engineer
• Keith Armstrong – assistant engineer
• Adam Fuller – assistant engineer
• Nathan Johns – assistant engineer
• Nik Karpen – assistant engineer
• Wesley Seidman – assistant engineer
• David Campbell – string arrangement
• Chris Lord-Alge – mixing
• Ted Jensen – mastering

Artwork

• Tara Podolsky – A&R
• Rob "Just Fine" Stevenson – A&R
• Jonathan Mannion – cover photo
• Patrick Hegarty – cover design
• Brian Lauzon – package design, photography
• Matt Taylor – package design, photography