I caught a substantial Gilbert & George show at Tate Liverpool in 1993, and I look forward to seeing the first retrospective in 20 years of their larger-than-life, slickly produced, performative photo collages. (The show debuted last year at Tate Modern, co-organized with the Brooklyn Museum.) Everything the duo has done in their 40-plus-year career, even their student work, is classic, from their Singing Sculpture (1968) —  in which they lip-synched and danced to a recording of the English music hall song “Underneath the Arches” while covered in metallic paint — to their “Naked Shit Pictures” series from 1995, which features photographs of their own excrement, predating by more than a decade Andres Serrano’s photographs of fecal matter that recently opened at Yvon Lambert in New York.