Fran & Marlow Cowan (married 62 years) playing impromptu recital together in the atrium of the Mayo Clinic. He turned 90 in February. The song is Old Grey Bonnet.
Here they are again on February 24th, 2010. Marlow is now 91, and his lover, Fran, is 84. This [act + butt slap] got them on Good Morning America.