Watch: Benedict Cumberbatch belts out Comfortably Numb with David Gilmour

Sherlock and Benedict Cumberbatch fans had the thrill of their lives when they got a chance to listen to their favourite star croon the Pink Floyd classic 'Comfortably Numb' on stage with David Gilmour, who was playing the third of his five-night residency at London's Royal Albert Hall to promote his 2015 album Rattle That Lock.Cumberbatch, 40, joined the guitar legend on stage for the encore and belted out a few verses of the song from Pink Floyd’s 1979 album The Wall. Originally sung by the band’s Roger Waters, Gilmour has often used a guest vocalist on the track during his shows. After the performance, Gilmour asked the crowd: “Who knew he could sing?”Yes, well this isn't the first time Cumberbatch is singing. He has performed 'Can't Keep It Inside' for his film August: Osage County (2013).Another one of Gilmour's famous guests who performed 'Comfortably Numb' with him was the late David Bowie: