Joshua Nathan Rubin is the founding clarinetist, and served as Program Director and then Artistic Director of the International Contemporary Ensemble, where he oversaw the creative direction of more than 500 concerts in the United States and abroad. As a clarinetist, the New York Times has praised him as, "incapable of playing an inexpressive note." He has performed as a soloist with the Seattle Symphony Orchestra, the Nagoya Philharmonic, as chamber musician with ensembles such as the St. Paul Chamber Orchestra, ICE, Wild Up, Monday Evening Concerts, and Tesserae Baroque. In the 2024-2025 season he will perform on the stages of Carnegie Hall, the Rose Theatre at Lincoln Center, 92nd Street Y, the Ojai Music Festival, The Phillips Collection in Washington DC, and Disney Concert Hall in LA. He served on the faculty of the Banff Music Centre's summer programs from 2016-2019, on the Ensemble Evolution summer festival at The New School, at the soundSCAPE Festival in Switzerland. He is on the faculty of the College of the Performing Arts at The New School. He was an Artist-in-Residence at University of California Santa Cruz and The City College of New in 2024, and in 2025 will perform at invited Artist Residencies at Harvard University, Oberlin Conservatory, Barenboim-Said Akademie, and University of Californias, San Diego, Irvine and Riverside.

He is also a software designer who developed LUIGI—arts management software used by over 700 artists, staff, and administrators in 2024—that is available to ensembles and other organizations who value transparency and collective management. He maintains an artistic presence in New York and Los Angeles.