How many French horns can play Wagner at one time?

The business of setting musical records does not normally have much to do with actual music. The longest an oboeist can play with circular breathing, the fastest piccolo player, the highest note sung by a human etc – these are not about music-making. A record of a rather more impressive order is due to be attempted at the Royal Opera House on Sunday, 23 October. The largest number of French horns ever gathered in one place will attempt to make music together.

Not just any music, mind. The arrangement they will be performing is the opening of the Ring cycle, the hauntingly atmospheric chorale which mimics the sound of the flowing river in Das Rheingold. The part is scored for eight horns. At the latest count, on this occasion there will be rather more than eight.

“Currently it looks as though from attendees only we’ll have at least 150,” says Roger Montgomery, the chairman of the British Horn Society which this year is holding its annual festival in Covent Garden. “With artists coming along we should have at least another 50. At the moment we’re looking at more than 200 players.”

Even more are encouraged. As the part consists of only rising intervals of fifths and fourths across a couple of octaves, it will not be a significant challenge even for the less competent player. I write with some authority, having once participated in New Hampshire in which 47 horns made a sound of bewitching quality. Multiply that by, say, five, and add in the resonant acoustic of the Paul Hamlyn Floral Hall in Covent Garden with its bouncy walls and high glass roof, and this will be a musical experience no horn player will want to miss. Montgomery, who is third horn of the Orchestra of the Royal Opera House and principal horn of the Orchestra of the Age of Enlightenment, advises that for non-horn players there will be an opportunity to play on certain percussion instruments or alternatively the wind instrument whose properties were once famously demonstrated by the great maestro Dennis Brain. I refer, of course, to the hosepipe. The people at the Guinness Book of Records have been contacted.

The rest of the day promises rich musical pleasures. There will be a strong emphasis on musical education as this year’s festival is jointly organised with the Royal Opera House’s education department. A group improvisation is being overseen by composer and ex-horn player Duncan Chapman. A series of segments from the Ring, arranged for large horn ensembles, will be accompanied by a spoken narration and will culminate at the end of the final gala concert with the BHS's traditional massed horn blow, this year the closing scene of Götterdämmerung. There are five parts, downloadable from the British Horn Society website.

“We’ll have the difficult parts taken by college students, professionals and the better of the participants,” says Montgomery, “and there’ll be other parts for absolutely all standards. The easiest part might only include two or three notes for people who’ve only just begun playing."

In other words, there’s still time to take up the French horn, have a couple of lessons and join in. You won’t, I guarantee, have a more rousing musical experience.

• The British Horn Society festival on Sunday, 23 October at the Royal Opera House. Book tickets on the Royal Opera House website or by phoning 020 7304 4000 or turning up in person at the box office