Ah, to dismiss classical music as elitist: it’s the cheapest trick in the book. Unfortunately, BBC broadcaster Clive Myrie – one of the BBC Proms’ presenters this summer –succumbed to this temptation. ‘This is music for everyone, not a select few who know their crotchets from their quavers!! That’s boring and naff!!’ he tweeted this month. Knowledge is never boring or naff. But classical music is uniquely accessible to those with enormous expertise and those with none.

Anyone who has had even one or two music lessons knows that notes look different depending on their length. There are (in British English) crotchets and quavers, and indeed semi-quavers, minims a few other types of notes. If you know your crotchets and quavers, you can make your way through a considerable amount of music. Generations of professional musicians and so-called simple folk have done exactly that. Factory workers playing in the brass bands that used to be commonplace in Europe – watch the still-playing Grimethorpe Colliery Band rehearse Johann Sebastian Bach here – worked in their factories by day and played crotchets, quavers, minims, semiquavers and the occasional breve or demisemiquaver in their spare time. What’s more, all kinds of Western music use the same system of musical notation.

For generations, classical music has been enjoyed by people of all stripes. Indeed, for a long time the music that we now call classical was performed primarily by amateurs, who gathered in homes and other improvised performance spaces to sing and play together. In courts, the duke, prince or other ruler often gathered musicians of varying abilities, sometimes including themselves, to perform. Frederick the Great of Prussia was an accomplished flautist and composer – though hardly a professional musician. Churches and cathedrals, meanwhile, trained countless children – who by definition started out with little expertise – as boy choristers. Even when music did start being regularly performed in designated spaces (opera houses, say), it was a decidedly relaxed affair. Even during Wolfgang Amadeus Mozart’s time, operagoers chatted and dined during performances, and the light often stayed on.

And classical music remains accessible today; it’s just that many people don’t realise it. Anyone, whether or not they’ve ever heard the word crotchet, can turn up at Westminster Abbey to hear world-class music. Next to them may be a musicologist specialising in, say, the history of counterpoint, but they’ll both hear the same music and they’ll both enjoy it, each in their own way. Anyone can buy a ticket to the Berliner Staatsoper, the Wiener Staatsoper, the English National Opera, or any of the hundreds of other opera houses that grace our cities – and it’s not even very expensive. In the upcoming season, tickets at the ENO can be had for around £15, at the Berliner Staatsoper for €12 and at the Wiener Staatsoper for €15. That puts classical music – performed live, by people at the top of their game – in the same price range as the Barbie movie.

And just like in the cinema, attending a classical-music performance involves being courteous to fellow audience members. When I recently attended a superb rendition of Richard Wagner’s Die Fliegende Holländer at the Berliner Staatsoper, the audience – a merry mix of young and old – sat in rapt attention in the darkened opera house. Everyone, that is, except a tourist next to me, who kept surfing on her phone. A fellow audience member gently enlightened her, and we could all enjoy the performance.

Yes, like any activity classical music has conventions, most famously the one that involves not clapping between the movements of symphonies and concertos. That’s to maintain the flow and integral nature of the symphony or concerto. It’s both common sense and easy to figure out by taking one’s cue from other concertgoers.

Last week I attended two BBC Proms. In one, the BBC Philharmonic conducted by Mark Wigglesworth performed Sergei Rachmaninov’s First Piano Concerto (with Sir Stephen Hough as the soloist) and Gustav Mahler’s First Symphony. In the other, the BBC Symphony Orchestra conducted by Josep Pons played Édouard Lalo’s Symphonie espagnole (a violin concerto, its name notwithstanding), with María Dueñas as the soloist, and works by Manuel de Falla, Claude Debussy and Maurice Ravel. Both times, a large audience had turned up at the Royal Albert Hall, some wearing jeans, some in more elegant outfits. Did most of the attendees of the first concert know that Sir Stephen is one of the world’s most esteemed pianists, or was it their first venture to a classical-music performance? We can’t know. But there was a great deal of enthusiasm and even clapping between movements – and that’s precisely what the Proms are for. With tickets starting at £8, virtually everyone can afford to spend an evening listening to music, whether or not they know how it’s constructed.

And the beauty of classical music is that the joy doesn’t wear out after you’ve learnt more about it. On the contrary, the more you learn about crotchets and quavers and every other aspect of musical composition and performance, the more fascinating it becomes. One academic has compiled a list of the more than 54,000 PhD theses, books and academic articles that have been written about Bach – and academics and musicians continue to produce PhD theses, books and academic articles that analyse the great master’s work in the most minute detail, while complete beginners enjoy the Brandenburg Concertos without knowing the first thing about Bach’s compositional techniques. Thousands of books have been written about Mozart, too, but people of all musical abilities enjoy the Magic Flute. Indeed, a new film based on the opera is now out on Amazon and iTunes.

Classical music doesn’t need to dumb down to make itself accessible: its genius is that it’s already accessible to people of every skill level. Which human pursuit can compete with that?