Rock fans lost one of their most talented pioneers this week, as Greg Lake, founding member of both King Crimson and Emerson, Lake, and Palmer, died Wednesday at the age 69. The legendary singer and bassist succumbed to “a long and stubborn battle with cancer,” his manager Stewart Young shared on a Facebook post.

Lake’s career is highlighted by his founding of not only the prog-rock genre as a whole but arguably the two most influential prog-rock bands during his time, King Crimson and Emerson, Lake and Palmer.

Lake first burst onto the scene when he founded King Crimson with Robert Fripp, who was a student of Lake’s childhood guitar instructor. The two formed a bond, and in 1969 would release their debut LP, In the Court of the Crimson King, a widely influential and highly praised landmark record which birthed the prog-rock genre.

However, Lake’s time with King Crimson was short as he would eventually have a falling out with the band. He went on to form the prog-rock supergroup Emerson, Lake and Palmer with Keith Emerson, who was with The Nice prior to ELP, and Atomic Rooster drummer Carl Palmer. The group would go on to release four albums with the trio, including their iconic LP Tarkus, which reached No. 1 on the billboards in the UK and No. 9 in the US. In total, ELP was a huge commercial success selling over 48 million records and cast a wide net of influence over rock throughout the 70’s and 80’s through their fusion of funk, rock, and jazz as well as their elaborate stage shows.

Titans of both prog-rock and metal have all remarked on the influence of Lake’s legacy, ranging from acts like Iron Maiden and Rush to Dream Theater, Mudvayne and even Nirvana all citing King Crimson and ELP as strong influences on their early sounds. Numerous influences on prog-rock heavyweights Tool have been cited throughout their two decade career, with Tool’s use of elaborate stage shows as well as the jazz style of drumming incorporated by drummer Danny Carey. Tool vocalist Maynard James Keenan at one point jokingly remarked that “Now you know who we ripped off,” while the band was touring with King Crimson.

The announcement of Lake’s death comes at a particularly bad time for ELP fans, as bandmate and co-founder Keith Emerson committed suicide earlier this year, passing away from a single gunshot wound to the head at the age of 71, leaving drummer Carl Palmer as the only surviving member of the group.

While the loss will surely be felt by fans and friends of Lake, his legacy will continue to live on both through the music he left behind and the countless bands and artists he inspired along the way.