John Greenham (4x Grammy Award Winning Mastering Engineer) is the principal engineer at Clearlight Mastering. Originally from the UK, John has worked in the San Francisco Bay Area, and more recently in Los Angeles. These days he can be found in Clearlight Mastering's main studio in Hollywood. John is a four-time Grammy winner and has received many Grammy, and Latin Grammy, nominations and certificates for his work. He’s also a trusted mastering engineer to Mark ‘Spike’ Stent, who he collaborates on projects with frequently.

Over the years he has worked on projects from a diverse group of artists including: Billie Eilish, Finneas, Bo Burnham, Ice Cube, Lady Gaga, Gwen Stefani, Billy Idol, Miguel, Mura Masa, Sigrid, The Marías, Gracie Abrams, Nessa Barrett, K. Flay, Cautious Clay, Steve Lukather, Los Tigres del Norte, Los Cojolites, Omar Sosa, and more.

Recent projects include The Script, Liam Gallagher, Charlotte Lawrence, Girl in Red, Take That, Joe Jonas, and more.