The material was filmed by Dublin filmmaker Sé Merry Doyle in July 1982.
Westlife will also performed their new song live on BBC1’s 'The Graham Norton Show' tonight.
Foo Fighters,Papa Roach, Enter Shikari, The Streets, Frank Turner and The Wombats have also been confirmed for the high-profile gathering.
Special guests Ghost and Bokassa will provide support on all dates.
The boardroom at Dublin's Fender guitars HQ has been dedicated to Rory Gallagher by Irish President Michael D Higgins in a special ceremony.