Recochoku represents the largest share of digital song sales in the Japanese market. While that is the case, "iTunes is irrelevant" is no longer the case, it seems.
http://recochoku.jp/special/1561/
Western acts.
4. Taylor Swift - We Are Never Ever Getting Back Together
19. Carly Rae Jepsen - Call Me Maybe
26. One Direction - Live While We're Young
90. Avril Lavigne - Bad Reputation