'I slept with the gallery boss - and his wife'

"If I had that collection now, I'd be lounging by a pool in Los Angeles," says George Melly ruefully. "I invested £900 in pictures: a Magritte, a Miro, a Picasso drawing, an early Klee and a Lucian Freud."

The jazz singer and writer has always had at least two strings to his bow - and that goes for his early bisexual activities, too. Outrageous, forward-looking, talented: and that's just his suits. For decades he has juggled with the career of "Revivalist" jazz singer (with Mick Mulligan's band and then John Chilton's Feetwarmers) and writer (the autobiographical Owning Up is out in paperback later this month).

Yet his first job after finishing his national service in the Navy was in an art gallery. In his youth he was fascinated by Surrealist art and indeed still is: a visitor's first glimpse of George, as he comes down the stairs from the bedroom where ill health keeps him for much of the time, is of the glass eyes gazing from each of his elaborate slippers. Still in his sailor uniform, he used to haunt the London Gallery and became friendly with the eccentric who ran it, ELT Mesens: "I went to bed with him and his wife."

To prevent George from becoming a journalist ("hyenas, scorpions, vultures") Mesens made him an artistic offer: "You can come and train here as an art dealer." The salary was £3 a week, far from generous even in the late Forties. In addition, George - or rather, his father - had to buy £900-worth of paintings from the gallery's stock, which he could keep or sell. At the time, the bottom had fallen out of the Surrealist market and £900 bought George the Magritte and other treasures. He gradually cashed them in to take his girlfriends to expensive restaurants. "I sold the last picture to buy a mile of Welsh fishing river."

Mostly, he was a dogsbody: "I was an assistant - or non-assistant. I was an inefficient employee." He would address 400 invitations to an opening but the odds were that Mesens, picking one up at random, would find a mistake. The light switches baffled him. He was generally late; the only excuse was "I was making love," and you had to use it sparingly. He was untidy to the point of sluttishness. He was shouted at: "I used to burst into tears." The result of the "daily bollocking" was that he is now totally punctual and obsessively tidy.

There were other fringe benefits: "I learnt a lot about pictures, how to hang an exhibition. For example, a 'portrait' - a tall picture - should be flanked by two 'landscapes'." After three years, he left to become a jazz singer. And indeed the journalist, ie hyena, scorpion and vulture we love.

George Melly at 80: Aspects of his collection is at the Mayor Gallery, 22a Cork Street, London W1S 3NA, 18 to 25 August