On the album ‘Master of Reality’, there is a short, eerie instrumental just before ‘Children of the Grave’ called ‘Embryo’. It sounds like it’s played on a bowed instrument, maybe a cello.
Any idea who wrote/played it? I always presumed it wasn’t a member of the band. There are no credits on the album for it, IIRC, and I think they did credit Rick Wakeman for playing keyboards on ‘Sabra Cadabra’ (on ‘Sabbath Bloody Sabbath’).