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.
A Shackteau is a humble, weather-beaten, structurally questionable shelter located in a spectacular or highly coveted place—Wales, Jackson Hole, Sun Valley, Crested Butte, coastal Maine, the Alps—where the building itself may be worth almost nothing, but the dirt, view, access, and mythology make it absurdly valuable.
In use:
Shackteâu - We thought it was an abandoned shed until the realtor called it a rare alpine Shackteâu with unobstructed views and listed it for $2 million.