Tomorrow Never Knows accidentally invented flanging.

Yes, “Tomorrow Never Knows.”

That’s the one. During the Revolver sessions, engineer Ken Townsend accidentally discovered flanging when he tried to sync two tape machines by pressing a finger on the flange (the reel’s edge). The pitch shift created that sweeping, watery sound. Lennon loved it.

It’s a perfect example of a happy accident becoming a signature effect. The song itself is already trippy — the flanging just makes it feel like you’re falling through a wormhole.

If you’re looking for the exact moment tape manipulation broke rock music, this is it.