to mask one's shaky live performance and/or unfamiliarity with the words of one's own songs by enlisting the crowd to sing instead, often for entire verses and choruses, in the manner perfected by Robbie Williams
Bono didn't seem himself when U2 played Glastonbury: he kept doing a Robbie and getting the crowd to help him out by singing on his behalf.
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. Penguin Books,1992. p. 38)