He and his live band have opened for Weezer (at Hammerstein Ballroom) and Coldplay (at Madison Square Garden), and have played at music festivals such as All Points West.
He has collaborated with Meghan Trainor, H.E.R., Cynthia Erivo, Leslie Odom Jr., Yolanda Adams, Chris Jackson, Don Sebesky and Steven Bernstein.
Walkley has also scored and written songs for several major motion pictures, including the Edward Burns films Looking for Kitty, The Groomsmen, Purple Violets, and Nice Guy Johnny, as well as the 2005 film Southern Belles, which starred Anna Faris and Judah Friedlander.
Walkley has also composed and licensed music for numerous national advertising campaigns, for clients such as MasterCard, General Electric, Mercedes-Benz, Starbucks, and Macy's.
He composed original music for the Ed Burns/Steven Spielberg TV Series "Public Morals" as well as the Nickelodeon television show Team Umizoomi, where he also provides vocals for UmiCar.