A protégé of Dr. Dre, Elizondo has worked with 50 Cent, Eminem, Linkin Park, Carrie Underwood, Fiona Apple, Mastodon, Ry Cooder, Twenty One Pilots, Nelly Furtado, Brothers Osborne, Lauren Daigle, Madison Cunningham, and Lin-Manuel Miranda, among others.

His songwriting credits include "In da Club" by 50 Cent, Eminem's "Just Lose It" and "The Real Slim Shady", "Family Affair" by Mary J. Blige, and Carrie Underwood's "Cowboy Casanova".

His musician father, Miguel, had a diverse record collection and Elizondo grew up listening to artists from the Beatles to Motown to Johnny Cash.

"[6] He went to Hamilton High School Music Academy, where he met future engineer Manny Marroquin and drummer Abe Laboriel Jr., who inspired him to devote more time to practicing in order to improve his technique.

He also played in bands with musicians such as Nels and Alex Cline, Vinny Golia, Peter Erskine, and in 1994, as his extracurricular gigs became more time-consuming, he left CSUN to focus professionally on music full-time.

Although their album was never released,[13] the experience provided Elizondo with an education in publishing and the record industry, and introduced him as a songwriter and musician to prominent producers including T-Bone Burnett, Glen Ballard, Matthew Wilder, and Matt Wallace.

As he became more in-demand as a session musician, he played on records by artists including Sheryl Crow, Ry Cooder, Fiona Apple, Perla Batalla.

[1][14] In 1996, Elizondo was booked as a session musician for the recording of The Album, by The Firm, a hip hop supergroup composed of Nas, Foxy Brown, AZ, and Nature.

"[1] Shortly after he signed his publishing deal, Elizondo began to work steadily on Aftermath projects as part of Dre's core creative team.

[15][16] He played on Dre's solo album 2001 in 1999, and continued to work closely with him for the next 11 years as a multi-instrumentalist (bass, keyboards, and guitars), songwriter, and producer.

[20][14] As Elizondo's success in the hip hop and rap genres continued to grow, he was sought out to work with pop, rock, roots and alternative artists.

[23] Extraordinary Machine received almost universal acclaim, with Rolling Stone writing that Elizondo had given the tracks energy, taking a "sad song and making it better.

"[24] That same year, he worked with Mavis Staples, Ry Cooder, Sheryl Crow, Eric Clapton, Alice Cooper, Burt Bacharach and Avril Lavigne, and in 2006, he played, wrote and/or produced music by Mary J. Blige, Gwen Stefani, T-Bone Burnett, Doyle Bramhall II, Christina Aguilera, and P!nk.

[28] The reviews were positive, with AllMusic critic Stephen Thomas Erlewine writing: "It Won't Be Soon Before Long is that rare self-stylized blockbuster album that sounds as big and satisfying as was intended."

Acknowledged as a collaborative effort between Elizondo and the band, the album earned "rave reviews"[30] with the BBC stating that it went "one step further in its bittersweetly effortless pop.

[14] The nomination brought increased attention to his multi-genre credits, resulting in a "slew of new projects that propelled him beyond the pop and hip-hop genres in which he had made his name.

A fan of Elizondo's work with Dre, in an interview with the Los Angeles Times Urban said: "He has a great rhythmic gift as a bass player, is an incredible drum programmer and multi-instrumentalist.

Using live cast recordings and a verse from Roots frontman Black Thought, Elizondo created a version of the musical's "My Shot" that became the first song on The Hamilton Mixtape, "setting the standard and attitude of the project."

Elizondo also produced "Satisfied," by Sia (featuring Miguel and Queen Latifah) and Andra Day's cover of "Burn", giving it a "classic, old-school R&B vibe with hip-hop drums and overtones.

"[44][45] Among others, during the last half of the decade, Elizondo worked with Ed Sheeran, the Jonas Bros., Young the Giant, K.Flay, NF, Walk the Moon and Brantley Gilbert.

[47] Teamed with co-producer Lin-Manuel Miranda, the film's "We Don't Talk About Bruno" was #1 on the Billboard charts for 5 weeks, becoming the longest-running #1 song in Disney's history.