Crabby Covers: A Musical

When listening to a musician perform a song they did not compose, can you readily identify what draws you to their interpretation of that song? Or, is it a little easier to pinpoint what is not working for you when someone covers someone else's material?

I enjoy both radical re-imaginings of songs - e.g. Joe Cocker's take on the Beatles song With A Little Help From My Friends -  as well as slavish re-makes like Simply Red's version of If You Don't Know Me By Now, a Leon Gamble & Kenny Huff composition first recorded by Harold Melvin & The Blue Notes. Both work for me in a big way because each feels true to the essence of the original.

On the other hand, what plausible explanation could be offered for skipping a significant chunk of a lyric like Prince did in his version of Joni Mitchell's A Case Of You? I suppose the purple one - BTW, someone whose original music I like a great deal - could be forgiven had he chosen to cover a song by a lesser lyricist, like say, Steve Miller (he of the infamous taxes vs. Texas not-even-close-to-rhyming couplet). But if you're going to do a Joni Mitchell or Paul Simon or Stephen Sondheim song, is it too much to ask for a cover to include a majority of the original lyric? After all, A Case Of You isn't even close to being as lyrically dense as the average Dylan or early Bruce Springsteen song.

Though I've got plenty of other examples why some covers work for me and why others annoy the hell out of me, I'm keeping them to myself until I hear from at least a few of you.