It is 8pm on a Tuesday evening, and I am busy annoying the Olympic associations of various Caribbean countries by asking them which national anthem will play if one of their athletes wins gold in Beijing. "You want to know what?" asks the receptionist at the Meat Market - a butcher that happens to share the same phone line as the Virgin Islands Olympic Committee.

"I just want to know if your athletes would listen to the US's anthem or that of the Virgin Islands."

"I don't know, son," she says. "All I know is we ain't gonna win no gold medal."

I have spent the last few weeks making calls like this because I have been trying to track down every single national anthem that might be heard at this year's Olympics. All 205 of them. My plan was to listen to all the anthems - the instrumental versions that you hear at the Olympics - with a music journalist's ear, and rank them; that way I would know who to cheer for. There is no other fair way to compare countries musically. National anthems are the same the world over - a short, classical piece meant to stir up pride. They have got to be boisterous and bombastic, with a tune simple enough that you can shout it whether drunk in a stadium, or drunk in front of the TV.

Little did I know that it would take a month to track down four hours, 26 minutes and 25 seconds of music, or that most of those tunes would be so tedious I would have to limit myself to five a day to stop them putting me ofbrass for life. I also didn't expect the search to create in me an undying hatred for both La Marseillaise (versions of which are used by seven countries) and God Save the Queen (used by three).

And what did I learn from all this? That there are only a dozen anthems that are musically worth listening to - and that most of the countries these belong to do not have a hope of winning a gold in Beijing.

Anthems go back as far as the 1560s, when William of Orange's family decided he needed a song, Het Wilhelmus ("The William"), to accompany his exploits fighting for Dutch independence against the Spanish. It is a peaceful song - calming, even - with a winding melody. In short, it is everything an anthem shouldn't be, which is perhaps why no other country developed an anthem for a good two centuries. God Save the Queen was not performed until 1745, La Marseillaise until 1792, and what is now Germany's - music written by Haydn - until 1797.

With colonialism, anthems spread world- wide, although most were not made official until the 1920s and 1930s. The first time they were used at the Olympics was 1924. But colonialism did not lead to every country adopting the hymns and military marches that pass for anthems in Europe. Three other types developed: folk anthems based on traditional melodies; "the Arab fanfare", common in Middle Eastern countries and consisting of little more than a trumpet flourish; and the Latin American "epic anthems".

The last group are by far the most fun. Most of them last over four minutes and are set out like mini operas. They have a rollicking opening section, in which each part of the brass section tries to outplay the others, a melodramatic, meandering middle section - oboes and flutes dominate - and an over-the-top finish.

All of which background is pretty irrelevant, as from listening to 205 of them I have realised there are actually just two types of anthem: the perfunctory, lifeless ones, and those that make the effort to be different. Shame that 190 fall into the first group.

Antigua's, for example, is a school assembly tune, not an anthem, while Sri Lanka's sounds like a nursery rhyme. There are dull military marches such as Malta's and Burkina Faso's, and dull hymns like Zambia's and Malaysia's. Whoever wrote them seemed to be aiming solely for a tune simple enough that parents could teach it to their children on a recorder.

The other big disappointment with the majority of anthems is that no matter which country they come from, they sound like they were written by a band leader from the Royal Navy. There are no cha-cha-cha rhythms in Cuba's anthem, no highlife guitars in Ghana's.

"There are historical reasons for this," says Derek Scott, professor of critical musicology at Leeds University. "The UK's was the first real national anthem in 1745. And it was adopted by dozens of other countries: Sweden, Germany, even Russia at one point. The idea developed that it was only the words that were important in expressing national character. The tune to God Save the Queen was seen as meaning 'national anthem' and the words were what made it appropriate to each country."

People know what a national anthem is supposed to sound like - a western military march - so they make sure theirs sounds the same. "Countries use anthems to put themselves on the world stage," he says.

In spite of this, there are a handful of anthems that do stand out - either because they use non-western instruments, scales and tunes, or because they take a western anthem and then toy with it, making it solemn or funny, and entirely their own. Most of the "Stans" of central Asia have anthems that sound like they could not have come from anywhere apart from former Soviet states. They trudge along in minor keys, filled with imposing strings and booming drums, as if written to accompany armies clambering into battle.

Then there are Nepal's, Senegal's and Nigeria's, all of which make use of local instruments. Senegal's is even called "Strum your koras, strike your balafons" after the instruments that play it. Guinea's, a military march, inexplicably has a 10-second "polka break" halfway through. Burundi's does a similar trick, turning into the soundtrack from a Bruce Lee film for 10 seconds before realising that perhaps it wasn't the best idea after all.

When you hear tunes like these, which are genuinely different and exciting - world music fans would be lapping them up if they didn't know they were anthems - it makes you wonder why others do not follow their example. But will you actually hear any of these at the Olympics? Well, Japan's should get several airings - look out, in particular, for Kosuke Kitajima in the 200m men's breast-stroke - but none of the others has actually won gold in either of the last two Olympics, so it's unlikely. "We only have six athletes going to

Beijing and they didn't actually qualify," says a spokesman for Bangladesh's Olympic association. Surely, then, all the more reason to cheer them for their music.

Be Upstanding: The ten best national anthems

Uruguay: National anthem

One of the most euphoric pieces of classical music I've ever heard. Banks of trumpets play crescendos to false endings - for five minutes. But somehow it works.

Bangladesh: My Golden Bengal

A wonderful anthem that sounds like it was written for a stroll along the Seine. It really needs Jacques Brel. Which is probably not what composer Rabindranath Tagore had in mind.

Tajikistan: National anthem

Written when the country was part of the USSR, it sounds like the music that plays in James Bond films when a Russian spy is about to cut off Bond's manhood. It doesn't try to soar, but frighten, and it's all the better for it.

Mauritania: National anthem

A trip into the heart of the souk, albeit a menacing one. The melody is so unusual that most Mauritanian's can't sing along to it, so pretend it doesn't have any words.

Dominica: Isle of Beauty, Isle of Splendour

A simple, spiralling melody stuck on repeat for 47 seconds, but there's such movement and elegance to it. Don't confuse with the Dominican Republic's, which is wretched.

US Virgin Isles: Virgin Islands March

It's Mary Poppins! One of the few anthems to literally pull out all the bells and whistles. This should be a soundtrack to a kid's film.

Senegal: Strum Your Koras, Strike Your Balafons

How can an anthem that name checks two local instruments in its title - a harp and a xylophone - be any less than brilliant? It's really two tunes - the first twinkles, the second strolls. But both are amazing.

Nigeria: Arise O Compatriots, Nigeria's Call Obey

Written in 1978 by the Nigerian Police Band, this should be an awful march. Fortunately it features relentless afrobeat percussion, which makes any tune outstanding.

Nepal: Hundreds of Flowers

Adopted last year, when Nepal's House of Representatives threw out the old, western-style anthem. This folk melody on strings and hand drums sounds like slowed-down bhangra. Shame it's probably unplayable by brass, so unlikely to be heard outside Nepal.

Japan: May Your Reign Last Forever

Solemn. So much so, it'll have you thinking of everyone you've lost for its duration. Rarely does an anthem carry such weight.

What's your favourite anthem? Have your say on the music blog.

· This article was amended on Thursday August 14 2008. The section of the above article with the subhead 'And the winning anthem is ...' attributed the Bangladeshi national anthem to an unnamed composer. In fact both words and music were the work of the celebrated poet, playwright, novelist, painter and composer Rabindranath Tagore, a Bengali Indian. This has been corrected.