The scene at last night's Roger Waters show in London was more than any Pink Floyd fan could have hoped for, as Floyd members David Gilmour and Nick Mason reunited with Waters, their former bassist, on stage.

Making good on an earlier agreement, Gilmour made an appearance at Waters' performance of the band's legendary 1979 album 'The Wall' at the O2 Arena in London. He sang his heavenly vocal part on 'Comfortably Numb' with Waters and then reprised his famous guitar solo perched atop the giant, titular on-stage wall. The scene provided a flashback for anyone who had seen Pink Floyd's early '80s concerts.

During the show finale of 'Outside the Wall," Waters and Gilmour were also joined by drummer Mason, wielding a tambourine as concert fans witnessed an impromptu on stage reunion of the three men for only the second time in 30 years. The first was 2005's absolutely transcendent four song performance at Live 8, which you should watch right now if you haven't already seen it.

Waters appeared with Gilmour at a charity function last July for a brief performance. In return, Gilmour promised him that he would later join him at a random tour date to sing 'Numb.' Fans have anxiously been awaiting the appearance of Gilmour since Waters' tour began last fall. While the guitar legend's appearance had been anticipated, the inclusion of Mason was a complete surprise to all in attendance.

Word of Gilmour's appearance was leaked via his official blog prior to the show with the message, "I should also remind you that tonight is most definitely a one-off.  David is not repeating his special guest performance at a later occasion, I’m sorry to disappoint those of you with fingers crossed and tickets for later shows."

The London shows are reportedly being recorded for future release. The special Gilmour/Waters performance of 'Numb' was captured and you can view the officially filmed clip below. Unfortunately, a posting on Gilmour's blog indicates that the performance will not be included on any officially released DVD.

This brief reunion comes on the heels of Pink Floyd-related news from earlier this week in which the band announced plans to roll out greatly expanded editions of their classic catalog of releases beginning in September.

Watch Roger Waters and David Gilmour Perform 'Comfortably Numb' in London