Rubenstein has collaborated with many spoken word artists, including Rick Moody; Jeet Thayil, English; Sarita Choudhury, book-on-tape version of Chitra Divakaruni's Mistress of Spices; Shebana Coelho, Blyton in Bombay for BBC4; Anne Fiero; Steve Potter; Ace Moore and Clarice Keegan. Paul has also worked with dancers, including Melody Liu, Hassan Christopher, Mew Chang-Tsing and Yoko Murao, and provided the live music for Playback Theater Northwest, an improvisational theater group, for one year.

Paul's first "multi-track" recordings were done at the age of 13, by recording onto a mono "boom box" and playing the results back while adding another source, recording to the tape deck on a home stereo system and repeating the process to add more "tracks". Rubenstein didn't play an instrument yet, so the sound sources consisted mainly of household items-- stretched, plucked rubber bands, a kitchen timer, a metal lamp struck like a bell, etc. He also enjoyed recording thunderstorms and crows.

In college at SUNY Binghamton, Paul engineered a world music and jazz radio show at WHRW in Binghamton, NY. Rubenstein voraciously explored the vast record library there, and spent time reading about music theory of various cultures in the school's music library. It was then he built his first instrument, the microtonal guitar.

Paul went on to invent more instruments, including electric, stringed instruments which can be bowed or plucked: alumitar, ubertar, cellotar, viotar, invisitar. Electric tuned percussion instruments include: electric saron, m'birangi. Instruments with an automatic, motorized component include: mechanical monk, m'birangi, ubertar, chariot. Pictures are online at ubertar.com/instruments.html.

Rubenstein moved to Seattle in 1992, where he studied Javanese Gamelan with Jarrad Powell and Maria Omo of Gamelan Pacifica, sitar with Jeff Lewis and oud with Maurice Rouman. Paul also picked up other instruments, including the Egyptian rebab and Chinese p'ipa.

Rubenstein started a rock band called Neem, which released a vinyl 45rpm single and an album on Vagrant Records.

Rubenstein and Viren Kamdar started Bakshish in 1995. Viren played tablas and other drums from around the world and Paul continued to expand his arsenal of instruments, inventing new things and learning more traditional instruments. Bakshish performed everywhere from rock clubs to museums.

Concurrently with Bakshish, Rubenstein collaborated with fellow musical instrument inventor Eveline Mueller-Graf to form Spacepeople, an experimental music group, and performed around Seattle and at the Olympia Experimental Music Festival. Paul is a member of Sonicabal, a haven for experimental musicians and sound artists.

Rubenstein studied music composition at Cornish College of the Arts in Seattle for a year before moving back to New York and attending the Master of Fine Arts program at the Milton Avery Graduate School of the Arts at Bard College. Paul received the MFA Fellowship for 2001, 2002 and 2003. Paul's main focus in recent years is recording-- building up his engineering skills and creating film scores. Rubenstein continues to expand and develop his use of microtonal scales and unusual timbres.

Paul developed the “Building Music” program for Urban Arts Partnership (formerly Working Playground Inc.), teaching New York City public high school students how to design and build electric guitars, amplifiers and square wave oscillators and to compose and improvise using microtonal scales. Paul introduces the students to digital recording and production techniques for capturing and presenting their work. Rubenstein prepares the students for a live performance of their original work at the Urban Arts Festival in Manhattan each year.