Ed Sheeran is showing off on his new album, “ No.6 Collaborations Project,” a set of 15 songs that feature a notably wide range of fellow stars — Justin Bieber, Meek Mill, Cardi B, H.E.R., and many, many more.

But there’s something gratuitous about the guest list, no? Rowdy American rappers, stern British grime stars, toothless pop singers, Chris Stapleton. It smacks of dilettantism. Flashiness. It’s a neckful of gold chains for a singer who ordinarily wears none.

But among centrist pop stars — the Taylors, the Katys, the Gagas and so on — no one is quite as adept amid a range of styles as Sheeran. He may have his roots in busking-folk pop, but he’s long collaborated widely and cross-genre.

But right near the top of this album, he stretches too thin . On “South of the Border,” which features Camila Cabello and Cardi B, Sheeran dips into a little Spanish, as has become de rigueur, and leans into the tired trope that going “south of the border” is where real freedom reigns. (Sheeran is British, so maybe for this euphemism he just means the Isle of Wight.)