He has performed and recorded with heavyweights Fred Wesley, Roger Waters, Gary Bartz, Bernard Purdie, George Porter Jr., Skerik, Melvin Sparks, Andy Bey, Reuben Wilson, Susan Tedeschi, Harvey Mason, Alec Ounsworth, Anders Osborne, Red Holloway, Chuck Rainey, Phil Upchurch, Mike Clark, Johnny Vidacovich, Joey Waronker, Mike Gordon, Brooks Nielsen, and Steve Kimock.

[6] Walter moved from his native San Diego to New Orleans in 2003, and subsequently reunited with producer Dan Prothero to record Super Heavy Organ with local legends Johnny Vidacovich, James Singleton, Tim Green, and Stanton Moore.

He released Get Thy Bearings, which pushed Walter's organ, piano, Rhodes and synthesizer to the front of a group rounded out by guitarist/bassist Elgin Park, drummer Aaron Redfield, sax players Karl Denson and Cochemea Gastelum, and percussionist Chuck Prada.

[11] In June 2022, Walter appeared on The Late Show with Stephen Colbert as the Hammond B3 organ player with musical guest (and Pink Floyd co-founder) Roger Waters' band.

Walter has performed on the Andrews' composed movie scores for Walk Hard: The Dewey Cox Story, Bridesmaids, Bad Teacher, Jeff, Who Lives at Home, Neighbors 2: Sorority Rising, The Five-Year Engagement, The Adderall Diaries, The Reluctant Fundamentalist, 20 Feet From Stardom, The Heat, Tammy, Sex Tape, Instant Family, The Big Sick, I Feel Pretty, Second Act, The Lovebirds, The King of Staten Island, Roadrunner: A Film About Anthony Bourdain, The Bubble, Totally Killer, You're Cordially Invited, and Pharrell Williams' Piece By Piece.

He has performed on the Andrews' composed television scores for the HBO series Togetherness, The Zen Diaries of Garry Shandling, Apple TV+'s Platonic, and the theme song for New Girl.