A self-taught musician, Sen started the band, "Indian Ocean", with Late Asheem Chakravarty in 1990. They were joined by Rahul Ram in 1991, and in 1991 by multi-instrumentalist Amit Kilam completing the quartet. Using Indian rhythms, melodies and folk music influences the band created a unique sound and soon achieved success; in following decades produced five studio albums, and a live album, "Desert Rain". Besides this a concert DVD, "Indian Ocean Live In Concert" of their two-hour live concert at the Garden of Five Senses in Delhi was released in 2008. "Leaving Home – the Life & Music of Indian Ocean" (2010) directed by Jaideep Varma, it became the first band ever in India to be subject of a documentary. At the 58th National Film Awards, the documentary went on to win the Award for Best Arts/Cultural Film.