I'd say jazz, because it's been performed and recorded in many more countries than country music has, and because it is almost always performed by combos or even orchestras, while many country recordings -- especially early ones -- consisted of just a singer accompanying him/herself or backed by one or two musicians.
As for the concept, I read the article and I'm still not sure how it would work. Would it play Beatles records on which John or George sang but not Paul or Ringo? Or would it only play records that were credited to John or George as solo artists? And no Everly Brothers until Don Everly dies? No Sonny & Cher until Cher passes on?