Q: Can see songs and albums in iTunes but can't play them

Recently upgraded to OS 10.8, itunes 11.1.2, and OS7 on ipad and iphone.  I noticed only purchased songs were showing up now on OS7 devices and trying a variety of settings in tunes sync (sync all songs, sync only checked ones, etc) still wouldn't send over my privately owned (copied from my own CDs) songs. 

Then in itunes on Mac, tried to play a song.  The album icon and song list are all there, but no song plays when clicking.

My itunes folder is on an external drive.  All song and albums are there when I look in finder window.  The library is correctly addressed in itunes preferences.  I consolidated the library.

In all cases, it looks like all songs are there in itunes, but nothing plays, and nothing syncs over to ipad or ipone.  Any ideas?