“Hey Soul Sister,” Train’s comeback single, brought the San Francisco band back in a big way: so big that the finger-snapping song was the top-selling tune on iTunes in 2010, according to the music download service.

“Sister” sold a staggering 4.6 million copies.

Katy Perry’s “California Gurls” featuring Snoop Dogg snagged second place, while Eminem’s “Love the Way You Lie” featuring Rihanna came in third (Eminem’s “Recovery” was the top selling album on iTunes, as it was at retail in general.

Rounding out the top 10 are B.o.B’s “Airplanes” featuring Hayley Williams,  Taio Cruz’s “Dynamite,” Usher’s “OMG,” Taio Cruz’s “Break Your Heart” featuring Ludicris,  Ke$ha’s “Tik Tok,” Lady Antebellum’s “Need You Now” and Eminem’s “Not Afraid.”