Risking frostbitten lips, our trombone-playing pilgrim serenades the elements at 6,000ft
19 July

Leave Chatel, determined to go far. Reach last house in village, owner emerges: "You must be a pilgrim! Fancy a drink?" Another good intention gone ... He's retired, a veteran of the Santiago and Rome pilgrimages, full of good advice. (The most important: never give up!) The drink becomes a four-course lunch, an anecdote with every morsel. Finally leave at 3pm, light of heart but heavy of stomach.

20-23 July

The hills at last! Northern massif of the Auvergne volcanoes. Imagine a snooker table with plastic cups hidden under the baize, some horizontal, some upside-down. Translation for walkers: flat, flat, UP! All covered in forest. Climb the Puy-de-Come (4,120ft/1,256m), its summit a deep crater covered in wild flowers. Beautiful. Peaceful. For five seconds. Then - "WAAAAAAAAH!" A Zulu impi! No, a school party. I flee the tumult, climb the Puy-de-Dome (4,867ft/1,484m), a ferociously steep pinnacle. With a road going up it. And a restaurant at the top. Busloads of tourists wave from air-conditioned coaches as I slog up. That's progress, folks.

On to the central massif, the horseshoe ridge of the Puy-de-Sancy (6,182ft/1,885m), the highest in central France and one of the finest walks in Europe - in good weather. I go up. Clouds come down. Reach the summit in sub-zero temperatures, howling wind, and a white-out. Confronted by 20 shivering tourists in jeans and trainers. Odd ... Drop down the far side. To a stairway, and a sign: "Cable-car this way". Is nothing sacred? Tourists flee. I unship the trombone and busk to the elements. Risking frostbitten lips, but it's a matter of principle.

24 July

Le Mont-Dore, health resort turned walking capital. Ask at the town hall for permission to busk. "You're a trombonist? Formidable!" What ho? It's the 50th anniversary of the Belgium-Auvergne Friendship League, and half the town's band is on holiday. Will I? Silly question. Meet the band: where's the trombone section? "You're it." Rehearsal? No time! Start marching at 8pm.

Following a Belgian band which set off at 7.55pm. Tour the town, end up at the Franco-Belgian Friendship Feast: mussels, chips, beer and a dance band. Who needs a trombonist? What can you do? No idea what we play, but it's all jazz. Show officially closes at midnight. Encores, 20 past. Then the Belgians take over. High on adrenaline, I join in. "C'est si bon", "When the Saints", "Scotland the Brave" and anything else we can remember. Or make up. And the dance goes on ...

For more information on the charity trombone walk, visit the website at www.netplaycafe.co.uk/bonewalk