jason gabriel mountario (jakarta, 11 june 1997) is a composer, arranger, producer, bass player, and mixing engineer. he is very much inspired by his father’s wide variety​ collection of music, from jazz, to rock, progressive rock, heavy metal, psychedelic, an old school jazz record, fusion, and pop. as a young kid, he was forced to take a piano lesson like everybody else, which didn’t last really that long until he discovered guitar, and things changed drastically ever since. his beginner music theory teacher who is a bass player taught him how to play electric bass at the age of 13, and jason became so obsessed studying his new instrument.
as time goes on writing also became jason’s second most interest, other than performing or you may call “practicing the bass”. he begun to write and compose his own music at the age of 14. jazz and psychedelic rock started to influence his styles of playing and composing. he tried to combine and composed a different kind of styles so that he eventually learned how to play a little bit of everything like a drum, percussions, voice, guitar electric, and keyboard. he won several school band competitions, as the leader of the band or sometimes as the favorite player. he also went for about 3 years to farabi (a well-known jazz institution in jakarta) and graduated as a bass performance.
in his final year of senior high school, he got a full scholarship from berklee college of music for his application towards berklee's summer program 2014. then he decided to pursue music as for his future career by studying at berklee college of music. he got berklee asia scholarship tour as well as berklee writing and composition scholarships from berklee. flew to america to become a full-time student until the present, majoring in jazz composition and performance.
he is very much focused on studying and expanding his taste of music as well as constantly composes a vast array of new materials. each piece represents his ability to appreciate and to be innovative to a different kind of style, crossing genre between jazz contemporary, to progressive rock, to singer-songwriter style, and pop music. 
producing shows every year has also become a top priority. so far, four have been accomplished.
The first one, he did when he was in his third semester, showcasing his first jazz contemporary compositions, experimenting with medium-large ensemble instrumentation. 
onto the following year, heading to the opposite world, which another show that represented jason's singer-songwriter materials. "RED across BLUE" materials encompassed electronic, progressive-rock and pop domain. around this time, collaborating with different people and releasing "pop" singles are a big part of the journey. the last single "even 20", gerald situmorang (an indonesian well-respected music producer, composer, and a guitar player) agreed to contributed and to produce. the final released closed the window of "pop" exploration and jason decided to pursue his jazz study much more intensely.
as time goes on, the study of jazz composition shifted and re-oriented jason's musical vocabulary. being exposed to jazz arranging and big band music inspired him in so many ways and once again, re-visiting the mind of jazz contemporary settings. within this period he kept releasing "single-works", mostly small-medium ensembles or big band pieces while working on some materials towards the next show.
third show delivered his brand new fresh original compositions and arrangements. it was a successful one, an exploration of a musical journey, crossing genre between rock and jazz, delivering a modern sound within the "classic" 6 horns jazz ensemble. in-fact, two of his materials won in two categories for the downbeat magazine 42nd annual student music award. his composition princess of sahara for “original composition-large ensemble”, and his rendition of nardis for “jazz arrangement”.
approaching his senior year, two student recitals need to completed in order to graduate. the second to last show was his performance major senior recital, presenting a quartet setting with the music of his "childhood" and another freshly composed original music, exploring the realm of modern contemporary - avant-garde sound. fifth or last show in berklee is scheduled to be a BIG BAND show.
he had been studying with some of the top teachers that’s been around in the music industry, such as billy kilson, bop pilkington, ayn inserto, omar thomas, greg hopkins, and many more.
Jason is also a self-taught mixing engineer, who mixed 95% of his works.
aside from music, he has a deep appreciation of another form of art. he did most of the artwork for his projects. photography, drawing, and movies could not be separated. his short movie "kilas balik" was nominated in the top 5 of indonesian short film festival 2015, while he was in the senior highschool.
and many more to come.