Music: The new beat generation

Kronos for Children

Royal Festival Hall, London

The star of the Kronos Quartet's Saturday afternoon concert for children was Craig Woodson, an avuncular instrument builder from Cleveland with a resonant voice.

He showed the packed hall he meant business by establishing three rules: "help your neighbour; ask your neighbour for help; if you have a problem - solve it!"

Good all-American rules for life, you might think, but Woodson followed this with a crisp set of instructions to turn a miscellany of household detritus - tubes, spoons, rubber bands, and so on, all dumped into a paper bag on each seat - into "drumpets".

The trumpet part of Woodson's invention is constructed from a strong cardboard tube, a plastic funnel and a sticking plaster mouthpiece. The drum is made from on of those transparent plastic containers that sandwich shops use for rolls or doughnuts. The plastic spoon became a drumstick.

Then he showed how to thread a nylon cord through a hole in the drum to make a crude string instrument, which Woodson demonstrated by rattling off a snatch of Eine kleine Nachtmusik.

The eerie rustle of a thousand-plus paper bags filled the auditorium as Woodson gave precise instructions about how to put the drumpets safely away before listening to the contemporary string quartet music of Kronos.

The musicians launched straight into Hammer and Chisel from John's Book of Alleged Dances by John Adams. Violinist David Harrington introduced Joan, Hank and John - first names only - and followed with John Zorn's Cat O' Nine Tails, which he compared to cartoon music. This clever collage includes hoe-downs, tangos and late-modernist scrabbling.

As a technical showcase it has plenty of surface fun for post-modern grown-ups, but the subsequent Anos Verdes (Song of the Green Ears) by Carlos Paredes was a beautiful piece that suited better the longer attention spans of the children.

Then came Jack Body's Ratschenitsa and Dumisani Maraire's rousing Mai Nozipo (Mother Nozipo), for which they invited Woodson back on for another instrument-building demonstration - he made a drum out of four pieces of wood and some parcel tape in about four minutes.

This piece made a great impact, and the audience clapped along at points - (mostly) on the right beats, in time and even observing dynamics. Kronos, whose robust and rhythmic playing is one of the great strengths of their work, were visibly impressed by this unexpected outbreak of British funkiness.

By this time, the children were dying to join in. Woodson called two other conductor-helpers on stage to man three sets of fluorescent signboards, with symbols for the six different ways to make a sound with the drumpet.

They gestured over the boards with large fluorescent frisbees and the audience followed the big, bouncing dots to play Raymond Scott's Powerhouse, which rattled along like a steam train - with antiphonal percussive punctuation by the massed drumpet-playing audience.

And for John Oswald's Spectre, the final piece, Woodson handled the large- scale graphic score boards alone - dashing across the stage with his frisbees like an avant-garde Rolf Harris, while Oswald's pre-recorded tape of up to 1,200 multi-tracked string quartets reached boiling point.

There were some amazing, dense, Ligeti-like sounds going on, it was exciting and fun, and in the words of a nearby grown-up, "liberating".

During a question-and-answer session at the end, one tiny boy asked: "What's the best place you have ever played?" Harrington replied: "Right here. Today!"

For the last word, I'll refer you to a quartet of actual drumpeters:

Jessica, age 12: "It's very exciting to sit down and find a paper bag - filled with bits and bobs you can't imagine would do anything - on your seat. You feel rather good once you've built your drumpet. The way in which you play the string part was rather unclear but everything else was OK. The first two pieces were not as good, but the rest were really great, especially the clapping one and the Green Ears song."

Billie, age 12: "I thought the drumpet man was cool - he should do a voice-over for The Simpsons. The music played by the Kronos Quartet was good, but a little too sort of 'we're hip and happening'. The idea is good, and I really enjoyed the audience participation. I think some adults wanted a drumpet more than the kids!!"

Rosie, age nine: "It was fun making the drumpet, but quite difficult to understand. Nice musicians, strange pieces of music. Funny names: some are peaceful and nice and some are quite dancey. They let the children ask questions at the end. Explanations very good: mostly by David."

Lilly, age eight: "Lovely music, nicely set and introduced. Nice blue and red lights."