Modern classical music is music written in the 20th century and beyond. Although much of it draws heavily on earlier forms, modern composers also experimented with rejection of long-held ideas; notably, Arnold Schoenberg questioned the traditional notions of harmony with his twelve-tone system[?], and John Cage questioned the very definition of music with his use of chance and found sounds.
... Museum[?], Leyland[?]
London
British Museum
Imperial War Museum -- see also Manchester
The London Institute
Madame Tussaud's
Museum of Moving Image[?] ...