Generations Apart, Radio 4, Monday &amp; Tuesday<br/>The Art of Water Music, Radio 4, Thursday

I wouldn't like to be 21 now. So many shops to loot, so little time... Sorry, cheap shot – especially as on the evidence of Generations Apart we have nothing to fear for at least some of the next generation of adults.

Radio 4's new three-year people-tracking project is focusing on two dozen-strong groups, 21-year-olds and 65-year-olds. Going out as it did in the middle of the riots, Tuesday's second part, featuring the youngsters, had an added resonance. With one exception, you couldn't imagine any of them chucking chairs through shop windows. They were imbued with a seemingly irrepressible optimism that I found immensely cheering.

In Kwabena Adjepong's case it's all the more creditworthy, given that he survived a horribly abusive mother and has been in foster care for 10 years. Now he's studying music and is a talented gospel singer; see him on YouTube. In two-nation Britain there perhaps should have been more than one representative of the underclasses – ex-jailbird Ricky Penn, who, we heard, gave his dad a good kicking on the kitchen floor. Compare and contrast Cat and her chums. She's just graduated from Cambridge, and her friend Flossie murmured, "We've done some incredible things, and the rest of our lives will be more of the same."

The 65-year-olds should be entering the seventh age, sans everything, including, for most of them, the prospect of immediate retirement. Carole threw herself into work when her disabled son died, worked her way up to station manager at Gatwick but is now losing her job. Her husband wants a divorce so they have to sell the house. She needs a new job, new house, new man, she says – "a completely fresh start".

And no slowing up, either, for Alice, who's bringing up Olivia, her eight-year-old granddaughter, because of her son and daughter-in-law's drinking. Alice, who's had a heart attack and breast cancer, and whose husband died three years ago, worries about Olivia's teenage years: "I'll need help." And Derek, who gave up work to look after his wife, who has Alzheimer's and doesn't know who he is. She's hard work: he has to feed her and dress her – "She doesn't keep still – imagine putting a bra on a worm" – but he refuses to put her into a home. At the other extreme there's Sandra and David who we meet exercising on the beach near their home on the Solent. They retired at 58, after both had bouts of cancer. Now they're training for the triathlon, and by the end of the programme they've qualified in their age group for the World Championship in Beijing. They made me feel tired.

With his 58th birthday hoving into view, Midge Ure shows no sign of slowing down either. In the fascinating The Art of Water Music, he investigated just what it is that makes music sound watery (lots of arpeggios and unusual harmonies, apparently). He did a vox pop by the river in Bath and played people Ravel's Jeux d'Eau, asking them to tell him what it evoked. Most got the picture, though one woman went the other way: "Fire – I could see Rudolf Nureyev dancing to this." But one man in particular had the soul of a poet. "A waterfall or fountain," he said, "or heavy rain that's easing off into showers pattering on water."