Why do so many jazz musicians live so long and pooh-pooh retirement? Because they have found the elixir of life in creativity and improvisation, that's why.
The octogenarian Lee Konitz said he had friends who had retired and now just stared at sport on the telly - certainly a kind of death.
He had no intention of following this path to oblivion which was why he was telling me this story at 8am after having played in Helsinki the night before, got up at four to catch a plane to England and was now entertaining me with anecdotes on the two-hour drive to Cheltenham for some more gigs there. He said he demanded payment for all the hassle of travelling round the world - the gigs themselves he played for free. After all, it was what was keeping him alive.
So, the elixir of life is most definitely contained in jazz music. You just have to hear Cleo Laine sing and John Dankworth play his clarinet for confirmation. They are currently celebrating their 80th birthdays and come to light the candles yet again at the Town Hall tomorrow evening.
Now, there have been visits to this city over the last couple of years by jazz legends who, let's be honest, were well past their musical prime. Our applause has been for their past achievements, tinged with that bittersweet edge acknowledging what we were hearing was but a pale imitation of what had once been.
No such qualms with the Sir John and Dame Cleo. They can still knock your socks off and so they will tomorrow evening.
The other thing that has always marked out Sir John as a leader is his impeccable taste in sidemen. Some are more recent acquaintances - trumpeters Guy Barker and Martin Shaw, and trombonist Mark Nightingale. Some go back further - pianist John Horler and drummer Allan Ganley (Dankworth first got to know Ganley well when they headed off to Paris in 1949 to go and see Charlie Parker play).
And some are family - the wonderful double bassist and son Alec.
Cleo at 80 may not have vocal range she had 60 years ago, but considering it was superhuman then, this is not necessarily a disadvantage - she just has a few fewer notes to choose from, and fewer dogs sitting up in surprise.
Yep, John and Cleo really can be considered British jazz's Liz and Phil, but they have done so much more than that hereditary monarch and her chum - there's all the education work and other showbiz stuff that goes on at their "home", the Stables in Wavendon, and there is all the jazz pleasure they have brought to millions down the years.
They symbolise that wonderful characteristic of British jazz - its classlessness and unassuming nature. You don't find airs and graces here, just more than enough puff to blow out 80 candles.
Dame Cleo Laine and Sir John Dankworth hold their 80th Birthday Concert with the John Dankworth Tentet at Birmingham's Town Hall tomorrow at 7.30pm. Tickets are £17.50 or £22.50 from www.thsh.co.uk or on 0121 780 3333.
And talking of our senior jazz citizens, don't forget that on Thursday Andy Hamilton hosts his traditional Blue Notes Christmas party at the Bearwood Corks Club. The doors open at 8.30pm and it's £4 (£3 concs) to get in. There's more info and how to get there online at www.bearwoodjazz.co.uk.