Believe me, the soft spot in my heart for the 70's is bigger than I like to admit. There was probably never a greater era in terms of the pinnacles of styles and growth. It was a true renaissance and everything done since then is a refinement. But music now is produced, engineered, written so well that the 70's has become a marker for what's happening now. There's still a little ways to go before someone today builds upon some element of songwriting craft like Boston's "More Than A Feeling" or Bread's "Everything I Own", just as examples. The Bread song is more cheesier and this may be an element to avoid, but there is a certain kind of "intent" to move the listener. Daft Punk's new single "Get Lucky" is a good example of the modern use of disco.