1974's 'Somethin's Happening' was an invaluable building block in Frampton’s development into one of America’s biggest stars of the 1970s.
Forty years later, this definitive performance by the original band has been restored from the original film reels, remixed and remastered.
The Kentucky rockers join a bill also including Foreigner, The Darkness and Beth Hart.
Foreigner, Anathema, Beth Hart, The Darkness and Chris Robinson Brotherhood have all previously been confirmed for Ramblin' Man 2019.
Justin Hawkins and company join a bill that already includes Foreigner, Beth Hart and Chris Robinson Brotherhood.
They will be joined on the Prog In The Park stage by Polish outfit Riverside and Pain Of Salvation, with further artists to be announced.
The news comes hot on the heels of last week’s announcement that Foreigner will headline the festival's main stage.
The UK festival will take place at Mote Park in Maidstone, Kent, between 19-21 July 2019.