There are two kinds of guitarists in this world: those who can play the Thunderstruck intro cleanly, and those who start it in front of people, get four bars in, and quietly develop a forearm cramp the size of Australia. I have proudly been both, sometimes in the same evening.
This little clip is Lick #8 from the series — the legendary AC/DC intro lick, the one built almost entirely from hammer-ons and pull-offs over a ringing open string. Thirty-one seconds, essentially one string, and enough fretting-hand stamina to make your arm write a strongly worded letter.
How the Thunderstruck intro lick actually works
Here's the nerdy truth: almost the whole thing lives on the B string, and the open B is the secret sauce. You hammer on and pull off to fretted notes while that open string keeps ringing between them, which is why it sounds like a machine gun made of arpeggios even though your picking hand is barely doing anything. The melody underneath is basically a B major scale climbing up the neck, but your ears hear a cascade, because the open string keeps butting in like a hyperactive metronome. Want a related workout for the same hand? Try the four-finger legato lick or the open-string drone idea.
The one genuinely useful takeaway: this is a stamina problem, not a speed problem. Keep your fretting hand loose, let the open string do the rhythmic heavy lifting, and practice in short bursts instead of one long death-march. Angus reportedly built it as a warm-up exercise, which is the single most Angus thing I have ever heard.
Nail it and you'll be the most insufferable person at every jam for the rest of your life — you're welcome. The PDF, the Guitar Pro file, and my ongoing forearm-rehabilitation fund all live over on Patreon.