Philip Trapp is a freelance writer and music journalist. He's written for Alternative Press, HM Magazine, Noisecreep, Music Times and others.
Watch: Robert Plant Plays ‘Immigrant Song’ for the First Time in 20 Years
The singer hasn't tackled the classic since the '90s.
Watch the Who + Jimmy Fallon Play This Classic Song on Toy Instruments
Things get silly on 'The Tonight Show.'