Afterwards, Yamaguchi made his first purchase of a traditional 4-beat jazz album, which was John Coltrane's Giant Steps. At the age of 20, Yamaguchi changed his guitar style completely into jazz under the strong influence of John Coltrane--developing his own guitar style by the perfect 4th tuning (E, A, D, G, C, F- from the bottom to the top). He also began to explore the imaginative formation of musical scales while majoring in English at Meikai University, Chiba, Japan (B.A. 1994). At the age of 26, he decided to study in the jazz program at the City College of New York where his idol, Ron Carter, directed; however, Yamaguchi was distressed about power harassment from some faculty members. During his college years, he performed with Chico O'Farrill's son, Arturo O'Farrill in the Graduate Jazz Ensemble. Whereas he was tormented by tendonitis, he professionally began to transcribe the recorded performances by John Coltrane, Charlie Parker and Miles Davis. In the end of 20^th century, Yamaguchi became the first native Japanese who completed their Master program in jazz performance from the City College of New York (M.A. 1999).

Masaya Yamaguchi is the author of the books John Coltrane Plays "Coltrane Changes" (Hal Leonard Corporation), The Complete Thesaurus of Musical Scales, Symmetrical Scales for Jazz Improvisation and Pentatonicism in Jazz: Creative Aspects and Practice (Masaya Music Services; formerly from Charles Colin Music Publications) and he has contributed articles to professional journals including Down Beat magazine, etc. Because of the reference value of Yamaguchi's outstanding achievements, the editors of Marquis Who's Who have selected his biographical profile for inclusion in Who's Who in America and Who's Who in the World. He lives in Manhattan, NYC.