I contacted one of the support people on the Apple Website. At one point it looked like I would have to delete the Music app, re-install, and then re-build my music library.
Then Vishnu- the tech support guy asked one very pertinent question-did I experience the same problem on every track?
I checked and basically the issue was only on a very recently downloaded album !
So the lesson is, if you have this issue is to check whether problem is one every track or just on one album.
I deleted the original download then re-downloaded it and everything works properly now. : )