Keith McIvor, better known as JD Twitch, of the influential Scottish electronic duo Optimo, died on Friday, September 19. The news was shared on the group’s Instagram page with a note written by McIvor’s bandmate, Jonnie “JG” Wilkes. Optimo did not specify McIvor’s cause of death, but the musician had disclosed, in July, that he was diagnosed with an untreatable brain tumor. He was 57 years old.

McIvor grew up in Balerno, a village near Edinburgh, Scotland, where he first rose to prominence in the early 1990s as a founding resident DJ at Pure, a party that ran at the Venue. In 1997, he linked up with Wilkes to launch Optimo (Espacio), a renowned weekly party at Glasgow’s Sub Club that ran until 2010, bringing in live acts like Grace Jones, Peaches, LCD Soundsystem, Cut Copy, and many others through its doors along the way.

McIvor and Wilkes also used the Optimo moniker for their own DJ sets, which were often marked by seamless, omnivorous music taste spanning acid house, post-punk, techno, funk, hardcore, and dancehall. Their work culminated in several head-spinning mixes, most notably 2004’s acclaimed double-disc How to Kill the DJ [Part II].

In 2009, McIvor and Wilkes formed Optimo Music, a record label on which they fostered both Glaswegian artists like Golden Teacher, as well as forward-thinking dance acts like Factory Floor. After bringing Optimo (Espacio) to a close, the duo continued to tour and DJ together across the world, including at additional residencies in Glasgow and London. Optimo also hosted a monthly NTS Radio show and recently launched Watching Trees, a music festival in the North Wiltshire countryside.

“In a 28 year partnership he changed my life immeasurably and together we took our work in directions and to places few people are lucky enough to explore,“ Wilkes wrote, in part, in his note announcing McIvor’s death. “I am forever grateful for everything he bestowed on me, both as a partner in music and as a friend. Keith’s intensity and passion for life, for music, for creativity and for positive change simply never let up. He was formidable.”