Jessica Duchen: Don't worry, Hitler preferred Lehar

If you have problems with the music of Richard Wagner, you aren't alone. It's almost impossible to take such a controversial genius easily on board for straightforward consumption.

There's a lot to deal with in his operas, which present a Gesamtkunstwerk, a "complete artwork" blending music, text, drama, design, incestuous twins, swimming Rhinemaidens, etc. First, there's the sheer scale of it all. Attend Tristan und Isolde and you'll be in the theatre for six hours. The final act alone of Die Meistersinger von Nürnberg is famously longer than the whole of Puccini's La Bohème. And at Bayreuth, Wagner's own theatre, they lock the doors so you can't leave in the middle.

Then there are the hefty doses of self-importance. A composer doesn't write operas shot through with the Norse gods, philosophical love-deaths, fictional Grail-seeking sects or massive paens to the supremacy of German art unless he has a somewhat exaggerated sense of his own significance.

Worse, he has the temerity to do all that and succeed. His works really are as significant as he thought they were – they changed the course of musical history – and his voice is so strong that it makes other music seem insipid. The only way to cope with Wagner is total surrender: when a listener takes one of his operas on its own terms, the effect is virtually mind-bending. Time begins to function in a different way; one does not listen to, so much as enter into, an entire world of irresistible sound. Wagner's ego negates our own. Admittedly, it's easier to allow this if the sopranos are not wearing winged helmets.

But the most difficult issue for many people is Hitler, who cleverly conscripted the power of Wagner's music into the branding of the Nazis – something that has been reinforced ad infinitum ever since. Therefore, whenever we enjoy a work by Wagner now, we can't help wondering if in some way we're in league with a force of evil.

Rest assured: we're not. It's true that concentration camp orchestras played Wagner while the Nazis sent their victims to their deaths; still, they played much else besides. It's also true that Hitler often attended the Bayreuth Festival – but there he was welcomed with open arms by the English-born Winifred Wagner (the composer's daughter-in-law) who adored him, and he could plan the invasion of Poland while the world assumed he was safely out of the way at the opera.

Bartok, in his Concerto for Orchestra, and Shostakovich, in his Seventh Symphony (both works with extra-musical associations), represented Hitler not with quotations from Wagner but with a phrase from Franz Lehar's operetta The Merry Widow, which in fact was his favourite. Maybe recognising this will make us feel better about enjoying Wagner.