After line check just to be sure all the electrons have a path back to the board we play something in which all the instruments play, and all the singers sing. Couple of years ago we were doing a town green show, and the LG (decades of performing experience) and I almost got into it (very unusual for this band) when he was satisfied with the sound check, but all we'd done is line check. "This ain't my first rodeo" he says. "OK, we'll see". Sure enough once the band started playing it was obvious to me that I couldn't hear my vocal monitor above the incessant blare from the back of the RG's amp in front of me, and my vocal monitor six feet in forward of that! I stopped the show (BL glared!) and motioned to the sound crew, who quickly rearranged the stage and the show went on. Funny, he doesn't give me any crapola about stage setup or sound check anymore!