The BBC Proms season is in full swing. By the time it has finished, London’s vast, 6,000-capacity Royal Albert Hall will have hosted 75 concerts over eight weeks, and most of these will be packed to the rafters or completely sold out. The only seat available for the BBC Symphony Orchestra’s Prom on 23 August is in front of the piano – and I’m taking that one.

Sadly, this is not the norm for classical music concerts. There are exceptions, but the general trend across the world is for audiences to be shrinking and ageing. It’s a complicated issue (and I embrace passionately those in our auditoriums with grey hair!), but with an art so rich and cherishable it can be frustrating to be reminded of the limit of its appeal.

Why is this? How can we encourage people to discover this treasure? Many ideas have been floated – better education, more creative repertoire, lower pricing, discouraging elitism. But what about the most practical aspects – the time a concert begins and how long it lasts?

At some point in the early 20th century we settled into a pattern: concerts should start early evening and last roughly two hours with a liquid interval, either to drink a glass of wine or visit the ladies/gents. Any shorter and we fear complaints from the audience; longer and we fear complaints (and overtime costs) from backstage staff. It’s important to address this issue if we want to refresh the experience of hearing great classical music live without resorting to gimmicks.

Traditionally in the UK, concerts start at 7.30pm and in the USA at 8pm. But on a recent recital tour I did in Australia the default time was 7pm. In Spain and Italy concerts can be at 9pm and later. The St Louis Symphony has 10.30am concerts, Atlanta Symphony has 6pm concerts, and the pianist Vladimir Horowitz in later life would only play at 4pm. Rock around the clock indeed.

But one thing common to all is the interval: the 20-minute space between first half and second half. In the opera house or ballet theatre this is understandable – sets need to be changed, singers and dancers need to rest, the works being performed are long and have breaks written into them. But who decided that a concert should last roughly two hours with a gap in the middle so we feel we’re getting our money’s worth?

I think we should consider removing the interval and starting either earlier or later than 7.30pm – 60 to 80 minutes of music, then out. The objection might be that the interval is a time to socialise. But is this really true? Isn’t it more a time to scramble to the bar or loo and at best begin a conversation which has to be cut short as you scramble back to your seat (“Where was I sitting?”) before the second half begins.

The Los Angeles Philharmonic has Casual Friday concerts when they play a shortened version of their programme with no interval and no on-stage dress code. I played one of these a few months ago and it felt charged with an energy that the traditional concert can sometimes lack. When you play for an appreciative, concentrating audience, there can be a cumulative emotional effect in the hall as you all enter the powerful world of a composer’s mind and heart. An interval’s descent to chit-chat can bring everyone down to earth with a bump and then require the engines to be started up all over again.

Another possibility would be to have two shorter concerts on the same evening, like sittings in a busy restaurant. A 70-minute concert at 6.30 then another one at, say, 9pm? It could be an exact repeat or have a slightly altered menu. People could even come to both with time for a proper meal in between or choose the one that fits better into their schedules. Concert halls with on-site restaurants could double the number of people they feed to the advantage of all, and we could have proper conversations with our friends, rather than shouting a few hasty words over the hiss of the hand-dryer.

Pianist Stephen Hough is live at the BBC Proms on Tuesday 23 August (7.30pm on Radio 3)