Jim Marshall, guitar amp pioneer, has passed away.

Born in London in 1923, Marshall started out as a drummer before going into business and founding Marshall Amplification in 1962.

He began making guitar amplifiers in Britain as a cheaper alternative to U.S. imports, and soon after legendary musicians including Jimi Hendrix and Eric Clapton were using his equipment.

He is revered as one of the four forefathers of rock music equipment along with Leo Fender, Les Paul and Seth Lover.

If you’re listening to rock and roll, odds are that you’re listening to music conceived or recorded involving Marshall amps.