Malan Singers, Classical Persian Masters, Queen Elizabeth Hall, London

As a tiny ethnic minority in a breakaway state, you can't get more marginal than the Malan singers of Taiwan. Nor could you find a more basic set of CVs: "Dives for sea-urchins"; "Grows leaves for wrapping betel nuts"; "As well-known for her voice as her liquor capacity".

And when the Malan singers marched on stage, clad in Peking Opera primary colours, you got the feeling they didn't really notice your presence. Grandpas and grannies, sturdy youths and maidens, they looked each other in the eye, marked the pulse with a stomp, and launched into song...

No, false start. After a ripple of mirth they began again. The first song translated as "Many Words, Long Thoughts", but as many of their words are merely onomatopoeic - Oriental scat - it seemed best to concentrate on the music, which was extraordinary. While the men's timbre was a ringing tenor, the women descanted like cats two octaves above. Then they changed roles, women below and men above, so that what seemed initially like basic call-and-response turned out to be complex polyphony. The whole thing was a capella, apart from hammered tree-trunks and ankle bells.

With the rice wine centre-stage, it was time for a musical game to drink your opponent off his little bamboo stool. Then we got a full-length drama compressed into five minutes, in which a keening patient was healed by a village shaman with the aid of song, herbs and clouds of expectorated wine. Full marks to the WorldVoice festival for snaring these rare birds.

Two days later, for Mohammad Reza Shajarian and his musicians, we were in Iran. With the opening preamble in Persian, we Brits again felt like eavesdroppers, but this time on an event of regal grandeur. Shajarian is the leading Persian classical singer, while spike fiddler Kayhan Kalhor, lutenist Hossain Alizadeh, and Shajarian's goblet-drummer son, Homayoun, make up the rest of this tradition's élite: sitting cross-legged, they launched into an hour of virtuosity.

It began with a slow burn, a duet between fiddle and drum into which Shajarian's warm tone gently inserted itself, with the lute adding instrumental spice. You didn't need to know this music's precise structure - codified a thousand years ago - to realise that its improvisations are rigorously controlled.

Here the voice was merely first among equals, but as Shajarian got into his stride the effect was spine-tingling. He creates surges of sound whose melismatic flights are delivered in something between a yodel and a warble: not for nothing was the nightingale - said never to repeat itself in song - the Persians' favourite natural analogy. As Shajarian caught fire, the others sparked too: Kayhan Kalhor's tiny fiddle - at times recalling a cello, at others a violin - did dazzling gymnastics over the drum sound. I was thinking how nice it would be to hear the lute on its own when something wonderful happened: as it embarked on a solo riff, the amplification cut out and there it was, pure, clean, the sound coming not from overhead, but from where the eyes led one to expect. For a moment it was perplexing: we forget how electronics alters how we hear.