The Philadelphia Folk Festival announced additions to the lineup for their 50th anniversary festival on August 18-21. Among the additions are The Levon Helm Band, Trombone Shorty and Orleans Avenue, The David Wax Museum, Jim Boggia, Suzie Brown and Jessica Lea Mayfield. They join a lineup that includes Jorma Kaukonen, Arlo Guthrie, the David Bromberg Big Band, Justin Townes Earle and many more. The complete lineup, ticket information and set times can be found here. On Thursday evening August 18th, World Cafe host David Dye will be hosting a special recording of sets by Amanda Shire, Terrance Simien and the Joel Plaskett Emergency. Below, a video of Trombone Shorty from a live broadcast he did on WXPN on June 4th, 2010.