Leyden's personal music score library, housed in an airy basement studio, included over 1,200 symphonic arrangements and 300 big band works. Into his 90s, Leyden continued to practice the clarinet every day. On Wednesday October 17, 2007, he conducted a 90th birthday concert with the 17-piece Norman Leyden Big Band at Portland's Arlene Schnitzer Concert Hall, titled Norman's Big Band Birthday Concert. He became one of just two classical musicians to be inducted into the Oregon Music Hall of Fame in 2008. He performed with Pink Martini in Seattle in August 2012, and on July 19, 2013, he debuted at the Hollywood Bowl, again with Pink Martini.