Christopher John Baran, widely known as CJ Baran, is an American songwriter, producer, and multi-instrumentalist celebrated for his genre-spanning approach that merges pop, rock, and alternative influences. Starting his career as a performer before moving behind the scenes, Baran has written and produced tracks for prominent global acts, blending catchy hooks with atmospheric arrangements. His ability to balance mainstream appeal with emotional depth has made him a sought-after collaborator in the international music industry.

CJ Baran has played a pivotal role in shaping ONE OK ROCK's modern international sound, contributing as a songwriter, composer, arranger, and producer across multiple album cycles. His collaboration began with One Way Ticket on Ambitions (2017), a track that reflected the band's push toward Western pop-rock sensibilities. He returned for Eye of the Storm (2019), co-writing and producing Grow Old Die Young, one of the album's most emotionally charged pieces.

Most recently, Baran co-wrote and arranged When They Turn the Lights On for Luxury Disease (2022), infusing it with a cinematic and anthemic quality that complements ONE OK ROCK's evolving sound. His contributions across these projects underscore his influence in bridging the band's Japanese rock roots with global pop-rock trends.