I COULDN'T raise myself for the National Dawn Chorus vigil earlier this month - though dawn is still the best time to hear birds singing ensemble, sending out their first-call signs for the new day. But listening from the garden at a more civilised hour, there was still plenty of carolling, even from newly-arrived summer migrants: a cuckoo calling from the allotments, a chiffchaff lisping in a neighbour's shrubbery. And there were plenty of common garden natives, too: chaffinches making their brisk, simple flourishes - almost identical in each bird, yet with local dialects in every part of Britain; song thrushes, with their re-peated phrases of piercing clarity, a species reviving after being badly hit by gardeners' slug-bait.

I'm always tempted in spring to try and compile a bird-song Top 10. But it is almost impossible for us, as post-Romantics, to judge the songs for themselves, free of the context of personal memories and associations. According to some recent straw polls, serious birders favour the curlew, whose bubbling song and haunting flight-calls evoke the kind of places that bird-watchers like best: winter marshes, high moorland, Dales hay- meadows in June. It is one of my favourites. But so is the whitethroat's song, as scratchy and unstructured as a bramble bush, yet redolent of the tangled hedges of childhood summers.

At the end of the 18th century, James Bingley drew up a league table of "the comparative merits of the singing birds of our own island". He awarded species marks for five qualities. The nightingale, quite rightly, came top on just about every criterion; but now that it is down to a few thousand pairs, chiefly in south-east England, would have to be disqualified as a "popular" songster today. The skylark was second, though it beat the nightingale for "sprightliness", and the linnet fourth, scoring high on "compass" and "execution". There are some oddities, signs perhaps of the taste of the times. The blackbird's languorous, conversational song, for instance - a favourite today - wins just four points for "mellowness" and nothing for "plaintiveness".

But we need to pull back a little here. What are we doing, making, as one species, aesthetic judgements on the communications of others? Presumably thrushes (low scorers across Bingley's scale) have exactly the compass they require. Yet the musicality we hear can't simply be dismissed. Only the most blinkered behaviourists now believe birdsong to be a purely functional business for proclaiming territory and attracting mates. Many birds improvise, mimic and sing for such needlessly long stretches that explanations based on selfish gene machismo can't be taken seriously. Birds plainly enjoy the sound of their own voices. Perhaps we have got the analogy the wrong way round. Perhaps bird-song is the template for our own musical stirrings - which is why we find it so affecting, and why it isn't sentimental or anthropomorphic to call the dawn cacophony a "chorus". !