Geoff Emerick, the sound engineer who helped to shape the sound of some of The Beatles’ most iconic releases, has passed away at the age of 72.

As Variety reports, Emerick’s manager, William Zabaleta, has confirmed that the legendary engineer passed away as the result of a heart attack.

“Today at around 2’o’clock, I was making my way back from Arizona to Los Angeles to go pick up Geoff so we could transport some gold records and platinum plaques to our show in Tucson,” explained Zabaleta in a video statement. “While on the phone with Geoff Emerick, he had complications and dropped the phone.”

“I called 911, but by the time they got there, it was too late. Geoff suffered from heart problems for a long time and had a pacemaker,” he continued. “When it’s your time it’s your time. We lost a legend and a best friend to me, and a mentor.”

Born in 1945, Geoff Emerick began working at EMI (later Abbey Road Studios) as an assistant engineer at age 15. Soon, he found himself working with the members of The Beatles, and oversaw their very first recording session for EMI back in 1962.

By 1965, producer George Martin personally requested that Emerick become the engineer of The Beatles’ music, and before long, Geoff Emerick was overseeing the recording of the Revolver track ‘Tomorrow Never Knows’.

During his time with The Beatles, Emerick served as the engineer for records such as Revolver, Sgt. Pepper’s Lonely Hearts Club Band, Abbey Road, and 1968’s self-titled record, commonly known as The White Album.

Famously, Emerick had a brief falling out with the group during the recording of The White Album, abandoning work after growing fed up with their constant in-fighting. However, he returned to work with The Beatles on Abbey Road the following year.

Geoff Emerick also managed to see major success following his work with the Fab Four, earning four Grammy Awards in his life, and working with artists such as Elvis Costello, Split Enz, Art Garfunkel, Badfinger, and Cheap Trick.

As Rolling Stone notes, George Martin biographer Dr. Kenneth Womack also released a statement praising the life and legacy of Geoff Emerick.

“Geoff Emerick was a groundbreaking engineer, particularly in terms of his eagerness to try anything and everything to meet his artists’ expectations,” he explained. “He famously captured John Lennon sounding like the Dalai Lama on a mountaintop for Revolver‘s ‘Tomorrow Never Knows,’ later bringing the Beatles’ career to a close in fine style on Abbey Road.”

“Like his mentor, producer George Martin, Emerick was always laser-focused on getting the best out of the track that his artists presented. Working at that granular level, he proved himself to be the greatest engineer of his generation.”

Check out Geoff Emerick’s work on The Beatles’ ‘A Day In The Life’: