They are all tracks from the Forever era done with Richard Stannard and Matt Rowe before they ultimately decided to work with Darkchild to obtain a more RnB sound. "Right Back At Ya" was the only song they kept, but the studio version had never fully leaked (obviously) and could only be heard on the Spiceworld In Christmas concert recording.
I'm tripping out so much listening to the full version of ADIYL, after listening to the bootleg version I stitched together with the leaked snippets for so long.