Question about MJ co-writing with other people

[analogue]

Here's a video of Brad Buxer talking about how MJ created the songs Who Is It and Will You Be There

http://www.youtube.com/watch?v=6wyxEM1_f4s

To me it sounds like that MJ wrote the bass part, the drum part and the vocal melody for Who Is It and then he and Brad worked out chords togther on the piano.

Now in this video Brad says that for Who Is It there was a drum track up and a bass line and he figured out some chords with MJ. Now if Brad was figuring chords out with MJ shouldn't Brad get a co-writing credit for Who Is It? Or does what Brad did not count as songwriting? My guess is that what Brad did was arrangement

I'm not trying to take anything from MJ's talent away but i'm just curious.

 

[MJ~And~Me]

I dont know, I think it was done between them:yes:

 

[Lucilla]

That could mean a lot of things.
It could be that at first they worked out the chords, MJ didn't like it and then MJ alone came with another chords, who knows.
Or probably MJ just needed him to play some instruments while MJ was humming what to play and Brad is just exaggerating little bit by saying they both figured out the chords.