We've all done it: heard an old song and thought to ourselves: "That must've been a Number 1!"
Some of the most famous songs in the world never even got to Number 1, while other long-forgotten tunes actually did make it to the top of the Official Singles Chart.
The thing about getting to Number 1 is it's what every song is aiming for – and it's an achievement that not every tune can unlock.
So, we've picked, at random, 30 songs – every one of them a hit – to test your chart-topper recall. You've got a 50/50 chance of success for each one, because the question is simple: Was it a Number 1? Yes or no?