This is an old debated topic amongst friends of mine who are MO fans. If you've ever listened to Sally Oldfield's music (and some of Terry Oldfield's too) you'll hear clear instrumentation that seems likely to have been inspired by Mike's music. Vibraphone parts that sound like Incantations or mandolin parts that sound like part 2 of Tubular Bells. The question is, does Mike actually ever play in Sally's albums? Some tracks (The late 80's piece Break Thru the Rock comes to mind) really sound like Mike's playing himself.
I know he's not credited, so it's unlikely that the record companies would allow someone as famous as Mike to play without putting his name on the cover. I personally suspect that the musical similarity is not coincidental, but a result of musical influence rather than Mike actually playing himself - but can someone please verify whether Mike has or has not ever performed on Sally's CDs?
I don't know if he plays on her records or not (I think not), but it wouldn't surprise me if the backing tracks have deliberately been made to sound like Mike. Mike was already well known when Sally stared her pop career, so many people (me included) checked out her music hoping that it sounded like Mike. "Mandala" is a great example. It's sort of modelled on the Guilty/Incantations formula with a vibraphone figure that's being transposed up and down.
-------------- "There are twelve people in the world, the rest are paste" Mark E Smith