Thank you Judith for your response. With regards to a link between the Sing family of Devon and the Sing family of London in the late 17th and early 18th centuries, there was also a William Sing who married Susanna Petty in 1712 at St Benet Paul's Wharf. Could he have been the twin brother of John Sing(s)? William and John Sing c. 15/02/1685 at Barnstaple. Also Joana Sing married William Turner in London in 1728. Could this be a Joane Sing c. 15/02/1685 Barnstaple?