While most successful sidemen are lucky to spend a decade in the music business, multi-instrumentalist Mark Rivera is working on his fifth.Rivera has shared the stage with some of Rock 'n' Roll's greatest performers, including John Lennon, Paul McCartney, Elton John, Simon & Garfunkel, Foreigner, Peter Frampton, Tony Bennett, Sheila E., Joe Walsh, Hall & Oates, and Peter Gabriel.How does he do it while avoiding the typical pitfalls—falling out of favor with...