Hi
To be honest, I'm not certain but I know through a good friend of mine there is at least 8 great releasable songs from each album (except Off The Wall) , and there are more songs from each era, that aren't as finished as well. That's supposedly what the Estate has. There are a lot of "finished" songs they don't have (Will I Am songs, Bahrain sessions, Red One and Bryan Loren sessions 1989-91)