Nestor Marconi is a leading player of the bandoneón, the small accordion-like instrument that is a prominent part of the traditional sound of the Argentine tango. He appeared on several recordings with Astor Piazzolla, the leading composer of the Tango Nuevo movement of the late part of the twentieth century. As such, he came into demand in classical recording circles with primarily classical artists, such as Gidon Kremer, Daniel Barenboim, Yo-Yo Ma, and Charles Dutoit, made cross-over recordings of Piazzolla's tango music, and employed side-men artists who had worked with Piazzolla on some of the original concerts and records of the works they proposed to record. Another recording project on which Marconi had a prominent part was an album of music songs by the leading classic tango composer Carlos Gardel with singer Marcelo Alvarez. Marconi is also the leader of his own tango trio with Leonardo Marconi on piano and Oscar Giunto on bass.