Some riffs need a seven-string guitar, a tuning chart and a signed waiver. This one needs three chords and the confidence of a man walking into a room he definitely wasn't invited to. Highway To Hell is the sound of AC/DC proving, yet again, that swagger is a technique — arguably the hardest one to actually teach.
In this clip I isolate the intro riff so you can hear exactly what's going on underneath all that denim and attitude. Just the A, the D/F# and the G, laid bare, so you can steal it, loop it, and annoy your neighbours with it before dinner.
How the Highway To Hell riff actually works
Here's the whole trick: the riff lives in A, and it walks A → D/F# → G → D/F#. The A and the D are exactly the I and IV chords your ear expects — polite, well-behaved, church-approved. Then in strolls that G major chord, which in the key of A is a bVII. That flattened seventh is the entire personality of the riff: it drags A major out of Sunday school and into A Mixolydian, which is the technical name for "sounds like rock and roll." If you want the deep dive on why one borrowed chord changes the whole flavour, that's the world of the major modes. The D/F# just means playing a D chord with an F# in the bass, so the low note steps down neatly from A to F# to G — a little bassline hiding inside the chords.
The concrete takeaway most people miss: this riff is built out of silence. Angus and Malcolm chop each chord short and let the gaps breathe, so the groove comes from what you don't play as much as what you do. Practise it staccato — hit the chord, mute it fast with your fretting hand, wait. If you can nail those rests, you've basically learned the AC/DC secret handshake, and you'll hear the same DNA in their other riffs too.
And yes, I know it's three chords. I have a whole shelf of music theory books and this glorious, dumb, perfect riff still outsells all of them combined. If you want the tab, the Guitar Pro file and roughly zero of my dignity, it's all on my Patreon.