Forbes contributors publish independent expert analyses and insights. Hugh McIntyre covers music, with a focus on the global charts.

The compilation will also involve songs from film soundtracks, including Eminem’s latest collaboration with CeeLo Green on the Dr. Dre-produced “The King and I,” from Baz Luhrmann’s “Elvis” biopic.

Eminem’s been at this rap thing for a very long time — and unfortunately, over the past few years, he’s started to show his age. While still as technically proficient as ever, the battle rap veteran ...