Susie Rushton: Good luck to the cast of Glee. But do they know it's already a crowded field?

Notebook

Brace your ears: we are now entering the peak of the season that musical taste forgot. For the next fortnight, you and I will have to endure more glam-rock jingling, more mawkish Fifties crooning, and more kiddies singing carols, than we strictly deserve.

Step into any sandwich bar, outlet of Gap, pub or even bookshop (sad, but true), and one is followed by the eternal playlist of Bing, Wizzard, John & Yoko and Slade. Why does it have to be like this? Because, secretly, that's what we really enjoy.

There's no such thing as a cool Christmas pop song, the closest contender being perhaps the New Wavey "Christmas Wrapping" by The Waitresses, simply because it sounds so deadpan and don't-care in an early-80s kind of way. But even in a genre where the tinkly sound of sleighbells and lyrics about "decking the tree" are mandatory, there is bad and there is good. The former, we all know; this year, it is summed up by Michael Bublé's album of croony covers, the imaginatively entitled Christmas.

But the latter – surprisingly good yule pop, the songs that you'll actually sing along to, if encouraged by enough alcohol – are much debated. On the musicians' website Music Radar, a poll by professionals put the Pogues' "Fairytale of New York" in the top spot of a chart that included Mike Oldfield's "In Dulci Jubilo" ("kick-ass guitar solo") and the Beach Boys' "Little Saint Nick" ("may have invented snowboarding").

The voting musos might have more populist taste than you'd think – The Pogues' drunken folk ballad, first released in 1988, just re-entered the charts this week at number 15. It was just trumped by Mariah Carey's "All I Want for Christmas is You" – recorded 17 years ago – which is now at number 12.

All we want for Christmas is familiarity, it seems. A successful Christmas song is a goldmine for any artist, because the sales keep coming in; Noddy Holder has referred to Slade's overplayed single as his pension scheme. Sometimes these singles aren't even particularly successful when first released, but keep selling over time. Also picking up a prize for the best snowy video, Wham!'s "Last Christmas" (1984) is the biggest-selling UK single never to have actually made it to No 1.

That gives a pretty good chance to this year's newest contender, a re-recording of "Do They Know It's Christmas" by the cast of Glee. Yes, the new version is a smoothed-out, Americanised rendition of the 1984 original by Band Aid – which featured "Simon LeBon's horrific over-singing", according to Music Radar – but it ticks the boxes for tradition, sleighbells and bouncy melody. Let Little Mix try to trounce that with their "Cannonball"!

Chocolate's dark secrets revealed

I went to the Chocolate Festival on London's South Bank this weekend in the innocent hope of buying a few affordable gifts, but the cocoa-dusted aficionados had turned the stalls into something of a bean-fight. It was crowded, and the goods not inexpensive.

Who knew that you could buy "single-estate chocolate" or that ganache tastes better if it's made from spring water? I tried basil-infused squares served at Michelin-starred restaurants, ethically-farmed Jamaican chocolate, and an amazing hot, spicy "Venezuelan chocolate shot" drink from the Choc Star van, the last word in chic street food.

What's clear is that our favourite confectionery is no longer a democratic sweet treat. The price of chocolate is predicted to leap because of a worldwide shortage of cocoa beans, and manufacturers could be forced to bulk out their bars with nuts or even air bubbles. The demand for dark chocolate and a growing taste for cocoa in China are pushing up demand and an area the size of Ivory Coast needs to be cultivated to satisfy our cravings.

There's never been a better time to, ahem, invest.