0:34 The First Heavy Metal Song.
Bullshit, the first TRUE heavy metal song was Black Sabbath by Black Sabbath recorded in 1969, BUT, here is a detailed song list of songs that were HEAVY and utilized power chords and harder elements PRE-1970:
The Kinks - You Really Got Me (1964)
Cream - Spoonful (1966)
Cream - Sunshine of Your Love (1967)
Jimi Hendrix - Foxy Lady, Fire, Purple Haze, Manic Depression (1967)
Blue Cheer - Doctor Please & Summertime Blues (1968)
Iron Butterfly - In-A-Gadda-Da-Vida (1968)
Steppenwolf - Born to be Wild (1968)
Led Zeppelin - Communication Breakdown, Days and Confused and all of first 2 albums (1968-1969)
King Crimson - 21st Century Schizoid Man (1969)
Pink Floyd - The Nile Song (1969)
Spooky Tooth - Evil Woman & Waitin' For The Wing (1969)
Black Sabbath - Black Sabbath (1969) - Had been playing the song since 1968
Then Deep Purple, Budgie, Trapeze, Iron Claw, Lucifer's Friend, Dust, Cactus, and dozens of prototype heavy metal bands.