All About That Bass

"All About That Bass" is the debut single by American singer-songwriter Meghan Trainor, released on June 30, 2014, through Epic Records. The song was included on Trainor's debut extended play (EP), Title (2014), and her debut studio album of the same name (2015). The track, a bubblegum pop, doo-wop and hip hop record, was recorded from 2012 to 2013 at the Carriage House in Nolensville, Tennessee and written by Trainor herself, alongside Kevin Kadish, who also produced the song. Trainor, who as a teenager struggled with her negative body image, was inspired to write the song to promote self-acceptance and body positivity.

Upon its release, some music critics praised "All About That Bass"'s production and memorable message, while others called it a novelty song and criticized the failure of its lyrics to empower every body type. The song was nominated for numerous awards and accolades, including Record of the Year and Song of the Year at the 57th Annual Grammy Awards. It was the best-selling song by a female artist during the 2010s in the United States, and was certified Diamond by the Recording Industry Association of America (RIAA). It also reached number one in 18 additional countries and received Diamond certifications in Australia and Brazil, as well as multi-platinum certifications in Canada, Denmark, Italy, Mexico, New Zealand, Norway, Sweden, Spain, and the United Kingdom, becoming the fourth best-selling song of 2014 with 11 million copies sold worldwide.

Fatima Robinson directed the song's music video, which features 1950s-inspired aesthetics and a pink pastel backdrop. The video was released on June 10, 2014, and played an important role in the song's rise to prominence. "All About That Bass" inspired parodies and cover versions, such as a parody from the cast of This Hour Has 22 Minutes, and covers from The Roots, Avi Kaplan of Pentatonix, and Maejor with Justin Bieber. Trainor performed the song on television shows and broadcasts such as The Tonight Show Starring Jimmy Fallon, the 48th Annual Country Music Association Awards (with Miranda Lambert), and The X Factor UK, and included it on the set lists of her concert tours That Bass Tour and MTrain Tour (2015), the Untouchable Tour (2016), and the Timeless Tour (2024).

After independently releasing three albums herself between 2009 and 2010, Meghan Trainor decided to write songs for other singers because she considered herself "one of the chubby girls who would never be an artist". In 2012, she signed a publishing deal with Big Yellow Dog Music, a Nashville, Tennessee-based music publishing firm, and moved to Nashville the following November. American songwriter Kevin Kadish met Trainor in June 2013 at the request of Carla Wallace, a co-owner of Big Yellow Dog. Kadish liked Trainor's voice and booked a writing session with her the following month. He said it was "like a blind date" because they had a strong song-writing affinity and a mutual love of pop music from the 1950s and 1960s.

Kadish read a list of potential song titles to Trainor, of which "All Bass, No Treble" was her favorite. Trainor was inspired by her teenage problems with self-acceptance and body image, and suggested these as a basis for the lyrics. She told Rolling Stone Kadish had experienced similar problems during his childhood and could relate to these themes. She suggested a booty theme with "it's about the bass, not the treble". Trainor was also inspired by Bruno Mars's "Just the Way You Are" (2010), and criticized the use of electronically edited images in beauty magazines. Kadish played a drum beat while Trainor sang the hook, "I'm all about that bass, 'bout the bass, no treble". Kadish and Trainor wanted to incorporate influences of 1950s doo-wop, a genre Trainor found catchy, into the song, which they wrote within 40 minutes. According to Kadish, he and Trainor equally contributed to the lyrics and melody, and Kadish finished the demo of "All About That Bass" two to three days later.

Although both were satisfied with the song, they doubted its commercial prospects. They pitched it to several record labels, who said it would not be successful because of its retro-styled composition and wanted to rerecord it using synthesizers, which Kadish and Trainor refused. Trainor sang "All About That Bass" for Paul Pontius, who was the A&R manager for Epic Records chairman L.A. Reid. She performed the song the following week using a ukulele for Reid, who signed her with the record label 20 minutes later. Reid decided that the demo, with additional mastering, should be the song's final cut. Speaking in 2015, he said he considered it "lightning in a bottle" and realized at their first meeting Trainor "was going to explode".

"All About That Bass" is three minutes and eight seconds long. The song was produced, engineered, programmed, sound designed, and mixed by Kadish—who also played drums, electric guitar, and bass guitar—at the Carriage House studio in Nolensville, Tennessee. David Baron played the piano, baritone saxophone, and Hammond organ. Trainor provided the track's clapping and percussion, and Dave Kutch mastered the recording at the Mastering Palace in New York City.

"All About That Bass" is a bubblegum pop, doo-wop and hip hop song. Kelsey McKinney of Vox characterized it as retro-R&B pop, while Slate's Chris Molanphy described its style as "vintage white-girl, Italo-Latin soul". The track has a 1950s-inspired throwback soul beat, and influences from 1960s genres—soul-pop, groove, Motown bounce and girl group pop. "All About That Bass" includes syncopated handclaps and bass instrumentation. In the song's outro, Trainor alternates between wordless vocal ad-libs and a pitched-down echo of "bass, bass, bass" at the end of the chorus mark. She raps some of the lyrics. According to Molanphy, it has "a scatting tempo and shimmying melody", which has been compared with South Korean group Koyote's song "Happy Mode" (2006) and American band Phish's song "Contact" (1989).