music , one of those lilting accordion waltzes , blared from the loudspeakers around the olympic-size piscine and , from time to time , echoing above the music , a man 's voice announced over the public address system that philippe bertrand , aged seven , was looking for his mother , that yolande lefevre was waiting for her friends below the dock at the entrance , or that a madame dufours was demanded on the telephone .