The last time I went to the opera was to see The Magic Flute. This opera features probably the most archetypal 'fat lady singing' aria anywhere – the Queen of the Night's Der Holle Rache, where the soprano must hit a high F several times.
The Queen of the Night that evening was a Russian named Albina Shagimuratova, who had the most extraordinary upper register and hit the top notes with force. She also happened to be on the larger side, to put it kindly.
But could a slimmer singer have done the same justice to Mozart's menacing matriarch? Or do the biggest voices need to be big in every way?
Dame Kiri Te Kanawa, the legendary soprano, says they do. In an interview with Radio Times, she says "you've got to have beef on you if you're going to sing".
At the same time, Dame Jenni Murray, the Woman's Hour presenter, has condemned the marketing of female classical performers, with the most attractive being pushed by record companies. She names violinist Nicola Benedetti and trumpeter Alison Balsom among "the ones who are prepared to go along with the old idea that sex sells".
There can be no doubt that there are violinists, trumpeters and other musicians who are just as talented as Benedetti and Balsom, but lack the glamour desired by record companies.
It is not exactly breaking news that sex sells, as I'm sure Dame Jenni accepts.
It is right to complain about the objectifying of young women in classical music and opera, but I find it difficult to criticise either Balsom or 25-year-old Benedetti, who, by the look of her website, does not seem to dress provocatively. There is no getting round the fact that she is beautiful. She also won BBC Young Musician of the Year in 2004 and has an established recording career.
Which brings me to Dame Kiri's remarks. In the 10 years that I've been going to the opera, the sopranos have ranged in body size.
Around the time of my first visit, Deborah Voigt, the American soprano, was sacked from a production of Ariadne auf Naxos for being overweight (she was 25 stone). After having gastric band surgery, she lost weight and was invited back.
Then there is the story about Maria Callas, surely the greatest ever soprano, who, it is said, 'lost' her voice when she lost weight.
I was not alive to hear her sing live, but I have a recording of a slimmer Callas singing Un Bel di Vedremo from Madame Butterfly and it is exquisite. Larger-than-average sopranos still get leading roles, but the best opera singers I've seen in the past decade are not women whom Dame Kiri would describe as having 'beef'.
It would not matter if they were overweight; it just so happens that they are not. It is not about being fat or thin if you have the voice.
The same goes for men. The best tenor I have watched on stage is possibly the greatest singer of his generation: Jonas Kaufmann. He is not overweight by any means. But, boy, can he sing.
It is probably the case that opera singers are simply healthier than they once were, with eating sensibly part of preparation for a performance along with rehearsals. Gone are the days when tenors would consume several bowls of pasta and a bottle of red wine before a performance.
Of course, no young woman – or man – should feel that they need to starve themselves to get the big role.
But we need to get over the fat lady singing.