Following a charity gig Waters performed Hold with his former Pink Floyd bandmates on 10 July 2010 , he confirmed Check that David Gilmour would guest on `` Comfortably Numb '' at one show during the tour .

Gilmour appeared Presence at the 12 May 2011 show at The O2 , London playing Participation lead guitar on `` Comfortably Numb '' and mandolin on `` Outside the Wall '' , on which they were also joined Becoming_a_member by Nick Mason on tambourine .