Tod Machover of MIT’s Media Lab invented the musical technology behind Guitar Hero, and here he talks about what’s coming next. Listen for some brand-new ways to interface with music — to play it, compose it, enjoy it. Machover then introduces Dan Ellsey, a composer with cerebral palsy who uses some new tools to write and perform his own music. Onstage, Ellsey conducts his “My Eagle Song,” in a soaring performance that underscores music’s power to move you and give you chills. (Recorded March 2008 in Monterey, California. Duration: 20:35.)