Roger Waters may not have made an album of new material between 1992 and 2017, but he was very active during that quarter-century. He toured regularly, wrote an opera, reunited Pink Floyd for the 2005 charity concert Live 8, and revived The Wall several times, turning the self-absorbed rock opera into a political piece. Is This the Life We Really Want?, his fourth song cycle, picks up on this thread, functioning as barbed protest music for the age of Brexit and Trump…