Firmin So is a legendary Hong Kong guitarist and music producer who rose to prominence during the golden era of Cantopop. He is widely regarded as one of the "Big Four" guitarists in the Hong Kong music scene, known for his technical precision and soulful arrangements.

In the mid-1980s, Firmin So was a founding member of the influential pop-rock band Blue Jeans (alongside Albert Lui and Tommy Chui). The band was known for hits like "Lan Ma" (Blue Horse) and their sophisticated, jazz-influenced pop sound. While not a singer himself, Firmin was so integral to the success of the "Four Heavenly Kings" (Jacky Cheung, Andy Lau, Leon Lai, and Aaron Kwok) that he was often a fixture in their recording sessions and world tours. He has served as the primary guitarist and bandleader for some of the biggest icons in Chinese music, including Leslie Cheung, Anita Mui, Faye Wong, Sandy Lam.

Beyond the guitar, So is a prolific arranger. He has the ability to blend rock sensibilities with polished pop production, helping define the "Hong Kong sound" of the 90s.Firmin So’s playing style is characterized by its versatility. Whether he is delivering a blistering rock solo or a delicate acoustic accompaniment, his work is marked by a deep understanding of melody. He transitioned from being a rock rebel in the 80s to a "Dean" of the session musician world, mentoring younger generations of musicians. 

“Firmin So isn't just a guitarist; he is a storyteller whose strings have provided the emotional backbone for decades of Canto-classics.”

In recent years, Firmin So has remained active as a judge for music competitions, a guest performer at major concerts, and a mentor. He is often seen participating in "Legends" concerts that celebrate the history of Hong Kong's vibrant music scene.