Among the founding associates from the influential globe music/fusion music group Shadowfax, Greenberg played flute, saxophone, and keyboards. The California-based musician was also popular for his usage of the Lyricon, an electric wind device he helped develop. The Lyricon added an ethereal aspect to his masterful melodic improvisations. Being a composer, Greenberg mixed rock and roll, pop, and jazz components into his music while keeping a progressive advantage. Greenberg died because the consequence of a coronary attack in 1995.