For some, the term ‘musical theatre’ can be enough to send shivers down the spine. The dramatists bemoan its triviality. The opera buffs ridicule its lack of musical merit. The public look on it as juvenile and just a bit of daft fun. So what it is about the genre that seems to keep shows running forever? Why do certain people go weak at the knees for the musical? And what is worth going to see?

‘Musical theatre’ is a broad term which covers just about anything (apart from opera) where there is a drama told with songs. It takes many forms: there’s the jukebox-musical, inspired more by an ageing pop group’s tax bill than any creative force. Mamma Mia, We Will Rock You, Jersey Boys: these are the fodder for the coach parties. There is the transfer from the cartoon film: Disney is the king of this. The Lion King and Aladdin give more tacky optimism and plastic merchandise than you can possibly take. And there is the familiarity of the film-turned-musical: The Bodyguard, Kinky Boots, Legally Blonde. All nice and predictable with a guaranteed happy ending. These are the junk food of theatre, where magical thinking and sentimentality reign supreme.

For the arty musical, Sondheim has been the go-to composer for those who want their theatre full of wit and intelligence. But even his winning of the Pulitzer Prize for Drama doesn’t prevent his shows closing early, or in some cases, not even getting to the West End or Broadway. Sweeney Todd, Sunday in the Park with George or Assassins reach a level of psychological intensity rarely seen in musicals. But if you’re after some tunes your grandmother mother would like, then head for Andrew Lloyd Webber. The Lord of the British Musical presents us with a mix and match of songs that haven’t changed much since the early seventies, but his monstrous commercial successes have more recently given way to disasters. His hidden gems of Aspects of Love and The Beautiful Game have now made way for his latest creation: a stage version of the movie School of Rock. We’re back to that predictability again: the happy ending is included in the ticket price.

But something has changed: the triumph of Wicked has heralded an age of shows written for every teenager who knows that their own personal problem is the most important thing to have ever happened to humanity. Its music, though, is still very much in the ‘show tune’ category.

Pushing it further was Spring Awakening, a musical where the contemporary soft-rock score finally reflects what the youthful cast would genuinely produce.

And now we have latest Broadway smash hit Hamilton where, rather than bursting into song, they abandon the idea of singing in favour of rap. It is a play about the Americans of then, told by the Americans of now. The cast is entirely African-American and Hispanic and the music is genuinely 21st-century. Hamilton has thrown aside 100 years of musical theatre tradition and it is tipped to spark a whole new era of spoken word musicals. It opens in London in 2017.

For those who don’t want to wait that long to be challenged by a musical, there are some fabulous pieces of non-commercial musical theatre to catch before then. Lazarus is an ethereal and through-provoking work by David Bowie. It showcases his sense of creativity and sincerity, and the original score isn’t just a collection of greatest hits. And if you really want to explore the darker side of theatre, then check out Whisper House (from the writers of Spring Awakening and American Psycho).

If you’re looking to expand your iTunes musicals library, then check out Jason Robert Brown’s Parade, a hugely moving and heart-breaking show about American injustice. Or Michael John LaChiusa’s See What I Wanna See, which looks in depth at the parallels between love and loss of different cultures and times. For new UK writers, there is The Go-Between by Richard Taylor, which has a melodic complexity that Britten would have been proud of. Or The C**t of Queen Catherine by Conor Mitchell, very much something for those who don’t want singing nuns, phantoms or boy meets girl tweeness.

There is definitely a lot more to the world of musicals than just watching Glee may lead us to believe. Cheesiness and superficiality have their place, but you don’t have to dig too far to find the real power of a good story told with intelligently written music