Gary Rees, the stepson and executor of the estate of long time Black Sabbath keyboardist Geoff Nicholls, has uploaded a rehearsal recording from the band to the official Geoff Nichols Archive YouTube channel along with the following message:

"This latest upload from the Geoff Nicholls estate I believe is called 'Slapback' from the scrawling on the cassette and the chorus. This is from the same cassette as the 'Heaven And Hell' upload on this channel. It doesn't sound like a typical Sabbath song if it is them, but it does sound like Ronnie James Dio. It must be a cover; any clues? I have no idea about anything, I wasn't there. Everything is speculation. Great tune by the way. Is it Ronnie on bass or 'a friend from Birmingham'?" 

Rees issued the following update when he shared the aforementioned "Heaven And Hell" recording back in January:

"I recently found this Sony C-90 tape cassette amongst the thousands in Geoff Nicholls' archive. On the inlay card is written 'ON & ON  HEAVEN & HELL  ORIGINAL VERSION GEOFF PLAYING BASS'. Inside the cassette case was a Maxell UD 90. The B side is written 'On + On HEAVEN HELL ORIGINAL  GEOFF ON BASS'. Nowhere does it say that this is Black Sabbath on the cassette. On And On Heaven And Hell may have been the original working title."

Recording lineup:

Ronnie James Dio – vocals
Tony Iommi – guitar
Geoff Nicholls – bass
Bill Ward - drums