The Times is doing a pop school this week starting today with the top twenty bands. They began with the Beatles and bravely left the Rolling Stones out (and Oasis). Glad to see T Rex there. Didn't expect Focus or Horslips but what about Creedence Clearwater Revival, Roxy Music, the Kinks, the Who?? Fleetwood Mac, Beach Boys, Slade was fair enough.
Bonhoeffer uses a similar phrase 'worldly Christianity'. It's J Gresham Machen that I want to line up most closely with. See his Christianity and culture here. Having done commentaries on Proverbs (Heavenly Wisdom) and Song of Songs (Heavenly Love), a matching title for Ecclesiastes would be Heavenly Worldliness. For my stance on worldliness, see 3 posts here.