11 March 2012 would have been Douglas Adams' 60th Birthday. To celebrate this event, Douglas's family and friends decided to hold a "virtual birthday party" in London, which turned out to be a stunning, star-studded event with chat, comedy and music filling the evening.

The event, which was benefitting two charities - the EIA (Environmental Investigation Agency), but mainly Save The Rhino - was a sell-out with devoted Adams fans taking the lion's share of tickets. When tickets went on sale in early December, there was a small rumour on Hitchhiker-related websites that David might be taking part, but all the sites which mentioned that very quickly removed all mention. Since then, there was no mention that David might be participating.

Of course, David and Douglas had known each other for some years. The original Hitchhiker TV series included a few bars from Shine On You Crazy Diamond, as "hummed" by Marvin the paranoid android. Later, Adams was to provide the title of the Floyd's final album, and subsequently appeared on their final tour one night in their Earls Court run in October 1994. The chances, then, of David participating in this event were inevitably quite high. And, to the delight of the audience, he clearly couldn't miss this celebration of his friend.

The HMV Hammersmith Apollo has undergone a few name-changes over the years, and is still best known as the Hammersmith Odeon, a venue which David performed at back in 1984 on his About Face tour. It's a small to medium size auditorium, seating around 3,600, so perfect for this sort of multi-faceted bill. A teatime start for the event added that wilfully odd edge to proceedings, which I'm sure Adams would have approved of. Of course, this also helped with the inevitable overrun of the show, as it still meant that attendees were out of the venue, and on their way home, at a reasonable hour.

Well before any thoughts of leaving, first we had to get in! Strangely, it took many of the audience a while to enter, as only a proportion were let in initially. This seemed to be related to the crowds in the entrance hall of the venue, but caused a little frustration to the rest of us. Thankfully, we were enjoying the spring sunshine bathing the front of the venue, which also had someone in a rhino costume wandering around, to help ease the mood.

The majority of the show was made up of assorted friends and admirers of Adams, talking science or nonsense (sometimes a cunning mixture of both) in the marriage of two of his favourite things. Given life again were various early comedy sketches he wrote, peformed by (in some cases) original protagonists.

With two of the main guests dropping out at the last minute (Professor Brian Cox, and comedian Stephen Mangan) some parts had a bit of a rough and ready feel, but this only added to the fun. After all, a unique man deserved a unique evening, and we certainly got that. Who else would have a tribute evening that would span everything from a sketch about kamikaze pilots (which opened the show), to eight rhinos tap-dancing in unison on stage, via a dalek, talk about the size (and beginnings) of the universe, and a couple of musical legends performing classic tracks of the 60s and 70s?

The final chunk of the show saw the screens onstage raise up into the rafters, as the talented band kicked off the musical segment, which held the audience's attention completely for the last half-hour or so.

It was quite a line-up - Robbie McIntosh on guitar and vocals, Gary Brooker on keyboards and vocals, Jodi Linscott on percussion, Wix Wickens on keyboards, Margo Buchanan on vocals and guitar, backed by Dave Bronze on bass, and Paul Beavis on drums. The pedigree shone through.

Part way through their set, and one final musician was introduced. Now, those who were alert before the show started had already noticed David Gilmour file in to the auditorium with Polly and some of their children, taking their seats in the stalls. That in itself was enough to get some hoping and anticipating some activity from David onstage. At various points through the show, Phil Taylor could be spotted at the sides, getting equipment ready, further adding to the frisson of excitement from some.

Anyway, on strode David, complete with an acoustic, ready to perform a nice rendition of Wish You Were Here. This was to be the sole Pink Floyd track (and vocal performance from David) for the evening though, handing his acoustic over in favour of the black Strat. This was for Too Much Monkey Business, a rock and roll song written and recorded in 1956 by Chuck Berry.

As the show's finale, Gary Brooker gave a great performance, accompanied by the whole band, of Procol Harum's classic A Whiter Shade Of Pale, which featured a great, sympathetic guitar solo from David, entirely in fitting with the song.

The full set list in the half-hour musical section, which concluded the four-hour show, was:

• Instrumental by Robbie McIntosh
• 'Dadi' (sung by Robbie McIntosh)
• 'Scarecrow' (sung by Robbie McIntosh NOT the Pink Floyd song)
• 'Rockstar' (sung by Margo Buchanan)
• 'I Just Want To Make Love To You' (sung by Margo Buchanan)
• 'A Salty Dog' (sung by Gary Brooker)
• 'Wish You Were Here' (sung by David Gilmour)
• 'Too Much Monkey Business' (sung by Gary Brooker)
• 'A Whiter Shade Of Pale' (sung by Gary Brooker)

A great way to end Douglas's "virtual" 60th birthday party, which the man himself would have loved...