[Delirium-Zer0]

On A BEST 2, "Greatful Days" has an extra bar of that sound effect that fades in at the very beginning. Otherwise everything's the same IIRC.

And AUDIENCE isn't, strictly speaking, different on A COMPLETE - they just used the Dave Ford mix instead of the album version. So it's just another instance (like TO BE and monochrome) of using the single version.