Owsley "Bear" Stanley, who fuelled the 1960s flower power generation with LSD and worked closely with the Grateful Dead, has been remembered as a man of "enormous influence".
Stanley worked as a sound engineer for the band and is remembered for the millions of LSD doses he manufactured at his lab in San Francisco, which helped to kick off the psychedelic era.
The 76-year-old died on Sunday in a car crash close to his home near Cairns, in far north Queensland. His wife Sheilah was also injured in the crash but has now been released from hospital.
Former Rolling Stones and Grateful Dead tour manager, Sam Cutler, says Stanley leaves behind a "long lasting legacy".
"Before LSD was legal he was one of the chemists in San Franciso who made it, and he made a lot of it. So he certainly had an influence on our times, as it were, on that level," he told ABC News Online.
"The psychedelic era is still with us. It's still out there happening, on one level or another.
"But that's just one aspect of the man - there are other things that he needs to be remembered for as well."
Cutler says his "brother, teacher and friend" developed music technology which is now taken for granted.
"When you go to a rock and roll concert, what you listen to is something in stereo sound. The person who invented that, and first brought it up, was the Bear," he said.
"The Grateful Dead were the first people to have a stereo sound system.
"Another thing he was responsible for were on-stage monitors, so you could actually hear what you were singing, or saying.
"Just those two things alone are major, major contributions to how popular music was presented to people."
Cutler says Stanley was a "rare and very special man" who was also a great artist.
"He was an alchemist, a wonderful man, a great thinker," he said.
"A very rare man, and very special. He's just an amazing man on all kinds of different levels.
"He made the most wonderful enamel sophisticated artworks - a kind of renaissance man of the 20th century. A bit of a Leonardo da Vinci for his time.
"He had enormous influence, in what he said and what he wrote - a huge amount of influence for just one individual.
"He affected the Grateful Dead but that was only one of the bands he had an influence on. Jimi Hendrix wrote Purple Haze as a result of the Bear's activities - there was an LSD of the Bear's called Purple Haze."
The guitarist, however, has denied the song's title takes its name from the drug.
Stanley is survived by his wife Sheilah, four children, eight grandchildren and two great-grandchildren.
Cutler says many more will mourn him following the fatal crash, which happened "on a terribly bad stretch of road that has killed lots of people".
"He has a large extended family in Australia and America," he said.
"He will be sorely missed by a great deal of people - including lots of people who loved the man dearly, who never met him but whose lives were radically altered by him."