What is the best-selling movie soundtrack of all time?

You probably already know this, but let's just make sure this is clear upfront: a soundtrack is a collection of songs either made for or chosen to be included in a movie, but a score is the music used to accompany what's happening onscreen. In other words, John Williams' compositions aren't in play here.

With that out of the way, it's high time we acknowledged the movie soundtrack, critical to a movie's success and at times more successful than the movie it was made for.

In some cases, soundtracks have also become hugely popular in their own right — but of all the great ones out there, which stands supreme as the best-selling ever?

Click START to answer.