Having not failed to sell out any of the dates thus far on their US tour, The Beatles only managed to sell 7,000 tickets for their only concert at the spectacular Red Rocks Amphitheatre near Denver, Colorado, leaving 2,000 tickets unsold.
There had been death threats. I remember going to one of their concerts at the Red Rock Stadium in Denver where Brian and I climbed up on a gantry overlooking the stage, and we looked down at the boys below during the performance; and the amphitheatre is such that you could have a sniper on the hill who could pick off any of the fellows at any time - no problem. I was very aware of this, and so was Brian, and so were the boys.
Prior to the concert The Beatles stayed at the Brown Palace Hotel. They took to the stage at 9.30pm; during the show they frequently felt out of breath due to the thin air in Denver, so oxygen canisters were placed on the stage for them to use.
Despite the unsold tickets, with this show The Beatles set a box office record for the open-air stadium. The event was the earliest notable rock 'n' roll performance at the venue.
On 26 August 2004 the Beatles tribute band 1964 re-enacted the concert, precisely 40 years after it first took place. Ticket sales are unknown.