Trying to work it out....

Got hold of Baptist Generals - Jackleg Devotion last week
As soon as I put it on I knew it was a very good album, samples had hinted
Where you stop what you are doing, I was at work, and think "oh yes !"

but

The singing is, shall we say, different, some would not like it at all
The instrument playing is not top notch, perhaps off key in places

So what is it that makes it so good, certainly for me ?
The chords progressions, the dynamics, a.n.other ?

I remember the same feeling when I put on Jeff Beck - You had it coming.
The same "this is something special"

Now you put this on a good system and the SQ is good

Upgrade the system and you have even more good

So what is it that makes an album, or a track so special ?
I'd really like to know what my head is doing