Place your first finger on the second fret of the A string. This is a B note. Place your third finger on the fourth fret of the D string. This an F-sharp note. Together these notes create a B5 power chord. Play the A and D strings together. Rest the heel of your right hand against the low E string to stop it from ringing. Play this chord once and let it ring for one beat.
Slide the chord shape down the fretboard so that your first finger is on fret five of the A string and your fourth finger is on fret seven of the D string. This is D5 power chord. Play it for one beat, then repeat it for a half beat.
Slide the chord shape further so that your first finger is on fret seven of A and your third finger is on fret nine of D. This is an E5 power chord. Play it for a half beat twice. The rhythm of the chords so far takes the pattern of, "One/B5, two/D5, three/D5 and/E5 four/E5."
Slide the chord further down so your first finger is on fret 10 of A and your third finger is on fret 12 of D to make a G5. Play this chord, then quickly slide the shape up to fret nine, then back to 10 to make a Gb5, then to nine, back to 10, then a larger slide back to fret five to make a D5. The rhythm of this phrase is, "One and two and three and."
Repeat D5 once and slide up to E5. Play E5 twice. The rhythm of this phrase is, "four and five," with an accent on "five." This completes the first repeat Iron Man chord riff.
Repeat the riff in its totality four times. The rhythm pattern of the entire riff goes, "One, two, three and four. One and two and three and four and five." "One and," "two and" and "three and" are each equivalent to two half beats."Four" is one beat. "And five" is two half beats. The chord order is: B5, D5, D5, E5, E5. G5, Gb5, G5, Gb5, G5, D5, D5, E5. The second half of the riff is faster and slightly more challenging. The chord shape remains constant throughout and you don't change strings at any point.