What do the following songs have in common: Jackie Wilson's Reet Petite, Rolf Harris' Two Little Boys, The Flying Pickets' Only You and Pink Floyd's Another Brick in the Wall? Throw in a couple of extra clues - Rage Against The Machine's Killing in the Name and Mr Blobby - and, of course, we can only be talking about the Christmas number 1.
Whether or not you rate the acts that have taken the top spot, it is an accolade that has stood the test of time - if only for the fact that it still marks the biggest-selling single of the year.
Arguably, the number-one spot was never really about credibility (see below). Nonetheless, the public distaste for force-fed pop is growing.
After a string of pre-packaged X-Factor winners reached the top spot, the nation fought back last year, with Rage Against The Machine beating the talent show's victor, Joe McElderry, to number one by more than 50,000 copies.
It was the biggest chart battle since 1998 when South Park's Chef and his Chocolate Salty Balls came close to derailing the Spice Girls' attempts to emulate The Beatles by having three consecutive Christmas number ones.
However, with this year's X Factor looking likely to deliver the poptastic goods once again - despite Facebook efforts to push The Trashmen's Surfin' Bird (a 60s song made popular again by animated TV series Family Guy) - is it time to simply let go of our nostalgic view of the festive single charts and let the Simon Cowell machine churn away?
We asked former DJ Bruno Brookes, now the owner of in-store music provider Immedia, which has just launched Dreamstream, a service that matches music to individual brands, and Gaz Coombes, the former lead singer of 90s Britpop group Supergrass.
30 CHRISTMAS NUMBER 1s
Year Artist/song title
2009 Rage Against The Machine Killing in the Name
2008 Alexandra Burke Hallelujah
2007 Leon Jackson When You Believe
2006 Leona Lewis A Moment Like This
2005 Shayne Ward That's My Goal
2004 Band Aid 20 Do They Know It's Christmas?
2003 Michael Andrews & Gary Jules Mad World
2002 Girls Aloud Sound of the Underground
2001 Robbie Williams & Nicole Kidman Somethin' Stupid
2000 Bob The Builder Can We Fix It?
1999 Westlife I Have a Dream/
Seasons in the Sun
1998 Spice Girls Goodbye
1997 Spice Girls Too Much
1996 Spice Girls 2 Become 1
1995 Michael Jackson Earth Song
1994 East 17 Stay Another Day
1993 Mr Blobby Mr Blobby
1992 Whitney Houston I Will Always Love You
1991 Queen Bohemian Rhapsody/
These Are The Days of Our Lives
1990 Cliff Richard Saviour's Day
1989 Band Aid II Do They Know It's Christmas?
1988 Cliff Richard Mistletoe & Wine
1987 Pet Shop Boys Always On My Mind
1986 Jackie Wilson Reet Petite
1985 Shakin' Stevens Merry Christmas Everyone
1984 Band Aid Do They Know It's Christmas?
1983 The Flying Pickets Only You
1982 Renee & Renato Save Your Love
1981 The Human League Don't You Want Me
1980 St Winifred's School Choir There's No One Quite Like
Source: The Official Charts Company
Diagnosis: Two experts on how the Christmas number 1 can get back in the groove
BRUNO BROOKES former DJ and chief executive, Immedia
The Christmas number 1 has never particularly been about credibility - just look at Mr Blobby. However, it used to be that every musician wanted that top spot; it was about how the power of the public could create the biggest seller of the year.
Now it's more about the power of Simon Cowell. As a result, people are not so interested.
A key problem is the lack of a TV programme, such as Top of the Pops or CD:UK, to promote bands. In addition, the internet is sporadic as a way for the industry to promote itself.
This is why we don't have the same peaks around the Christmas number 1 sales as we saw in, say, 1986 when the Christmas charts attracted 17m listeners.
Top of the Pops was always a springboard to selling huge numbers of records. Now The X Factor is the nearest thing we have when it comes to the marriage between music and fashion, but really it is only about self-promotion.
If the only way you can get to number one is by winning a TV show, then people will soon tire of the predictability.
- To get people interested again, the BBC should create an audiovisual Top 40 that runs across TV, radio and the internet. It could be a way for the BBC to gain ground on The X Factor. As well as chart sales, it could go to a public vote, perhaps also including smaller bands discovered online.
- This could generate a new platform for musicians and give people a constructive way to re-engage with the industry. Everyone could make a difference. It could become the people's chart again.
GAZ COOMBES, musician and former lead singer, Supergrass
Shows such as The X Factor don't really apply to me, as I can't relate to that school of thought.
I can understand the thinking, and even appreciate certain things - it's just not something that fuels my passion.
Pop stars have always been there. I remember when we first started with Supergrass (in the mid-90s), Top Of The Pops was in really bad shape, with lots of one-hit wonders.
Then suddenly Oasis came along and there were guitar bands throughout the top 10.
The thing that troubles me is whether indie bands really exist any more. There is a commercial hunger these days that I'm not sure up-and-coming bands have to the same extent. I find that a bit worrying.
Nowadays bands can get a million hits on YouTube - it's a different way of going about it.
You have to do what feels right for you as an artist, for the way you want to go about it.
It has taken me quite a long time to get my head around things such as Facebook; communication technology is moving so fast, so it's about picking up on the useful tools.
- Don't panic - it's all cyclical, and there is usually an eventual backlash against the commercial saturation.
- Have an old-school attitude in a fast-moving world and retain an ethos you believe in. With technology, there are so many ways of reaching the same spot.
- Everybody wants to have break-through songs, you need to have ambition and drive to be successful, but how you go about it is just as important.