J. Mattias is a rising voice in contemporary jazz arranging, known for their sophisticated harmonic language and innovative reinterpretation of classic jazz standards. With a background rooted in both classical theory and improvisational jazz, Mattias brings a fresh perspective to the genre. Their two distinctive arrangements in the jazz band library catalog showcase a keen ear for ensemble voicing and a commitment to expanding the traditional big band sound. Mattias's contributions are steadily enriching the repertoire for modern jazz ensembles.