Today in history, December 10, 1965, the Grateful Dead - or the 'Dead, as their fans knew them - played their first ever concert at the Fillmore Auditorium in San Francisco.
Over the next three decades, the Dead gained a fan following regarded as one of the most fervent in music - nicknamed "the Deadheads" - and became regarded as the psychedelic era's best-loved ambassadors.
Although the death of Jerry Garcia, founding member and guitarist, in 1995 signaled the end of the Grateful Dead, their legacy continued to grow.
The Dead's music - an unprecedented mix of rock, folk, bluegrass, blues, reggae, country, jazz, psychedelia, and space rock - remained in an orbit firmly outside the mainstream.
However, their long history and ardent following has seen Grateful Dead memorabilia make a big impact on the collectors' markets over the years.
In May 2007, a San Francisco auction of items owned by the group's long-time tour manager, Laurence "Ram Rod" Shurtliff, saw many Dead memorabilia items sell for six figures.
Highlights included a 1975 cream coloured Travis Bean guitar played by Jerry Garcia, which left the auction block at an impressive $312,000.
And, incredibly, a leather guitar strap worn by Garcia onstage around 1973 brought $20,400 - four times its estimate.
Meanwhile, a flight case containing Garcia's picks, unopened guitar strings and other accessories sold for $16,800.
Spurred on by the San Francisco sale's success, Bonhams went so far as to stage its own Grateful Dead-dedicated auction, More Skeletons from the Closet, in October 2008.
While a vast collection of new Grateful Dead live recordings flooded record shops after their disbandment in 1995, a collection of 840 cassette tapes featuring the group's live recordings between 1990-95 - recorded by their sound engineer - sold for an impressive $12,000 at Bonhams.
Unsurprisingly, vintage guitars also proved popular at the sale. A sunburst Fender Precision bass guitar played by band member John Kahn, used both live and on record from the 1960s-90s, brought $18,000.
Sold for an incredible amount, however, was a concert poster by founding band member Ron "Pig Pen" McKernan, entitled 'Can You Pass the Acid Test' from January 22, 1966.
It sold for $30,000 - a staggering amount for a band poster.
This was no doubt due to the importance of the gig (which also featured Allen Ginsberg) and its provenance: rooted firmly in the 1960s hippy culture that the Dead helped to define.
In another testament to how ardent fan worship can translate into ardent bidding, band manager Rock Scully's metal attaché tour case, used from the 1960s-80s, brought an amazing $33,000.
The success of Grateful Dead memorabilia is an important reminder to collectors: that it is a band's lasting impact and legacy, rather than commercial success, which determines the future value of their memorabilia.