The term 'BIG BAND AND GASLIGHT' can be summarized as the ERAS of jazz music and theater. The crossword solution for this term is ERAS, which stands for a period of time in history. Big Band was a style of jazz music popular in the 1930s and 1940s, while Gaslight was a type of theater popular in the late 19th century. Both of these ERAS were influential in their respective fields and have had lasting impacts on modern culture.