Well, we finally know who’s still out there buying CDs. Billboard reports that the biggest-selling CD release of the year is a box set called Mozart 225: The New Complete Edition, which sold 1.25 million copies in its first five weeks.

What is Mozart 225: The New Complete Edition? It’s a collection featuring every piece of music Wolfgang Amadeus Mozart ever wrote, released in October by UMG to commemorate the 225th anniversary of Mozart’s death. And apparently it’s very popular.

There’s a bit of a catch though: the Mozart box set is massive — we’re talking 200 CDs massive — and Billboard counts each CD as a separate sale. So, in real terms, around 6,250 box sets of Mozart 225 were sold. For comparison, Spotify’s most-streamed artist of the year clocked in at 4.7 billion streams. It was Drake.