Guitarist Lee Harris is showing off how one of the haunting sounds in Pink Floyd s early masterpiece Echoes , was created.

Harris currently plays on the song as part of Nick Masons Saucerful of Secrets , a band led by the Floyd drummer that recreates the groups pre-Dark Side of the Moon material.

The sound in question is commonly called the seagull, because thats what it sounds like. But Harris said its actually a guitar sound and originally the result of a mistake when Pink Floyd guitarist David Gilmour s wah-wah pedal was wired wrong. Instead of the expected wah-wah sound, the guitar produced that haunting gull-like sound, which Gilmour used on Echoes and later reused on Is There Anybody Out There ? on The Wall.

It turns the guitar into a sort of primitive synthesizer, Harris explained in a video posted on his Facebook and Instagram pages: