Even in the world of art, even in the most seemingly abstract(ed) of arts, institutions and institutional thinking prescribe the limits of the conceivable and acceptable. Juxtaposing a theoretical sketch of institutions in general terms – drawing especially on work in economics, sociology and political science and the artworld theories of, among others, Arthur Danto, George Dickie and Howard Becker – against brief paraphrases of or commentaries on musicological writings which deal with the institutions of post-war new music, I show here this process in action, as well as, hopefully, suggesting the relevance such a theoretical approach might have for mainstream musicology.