David Bowie demo is set to go under the hammer later this week.The track, ‘I Do Believe I Love You’, will be auctioned in Chippenham on Friday (July 23) and is expected to fetch up to £5,000.It was recorded when Bowie signed as a songwriter to Orbit Music in 1966.The demo was discovered by a London-based seller who found it in their back catalogue collection.It is amongst several other rare Bowie items being sold at the auction at Wessex Auction Rooms, including a signed copy of the singer’s