Music, artful arrangement of sounds (1) _______ time. This definition is obviously very broad, but a narrower one would exclude (2) _______ much. Music is part of virtually every culture on (3) _______, but it varies widely among cultures in style and structure. Definitions of music can (4) _______ dramatically over a short time, as they have across the world during the 20 ^th (5) _________.
 Can music exist without (6) _______? Some philosophers argue that music should be defined as a kind of "mental (7) _______" and that the physical aspects of sound are simply by-products of this image. If you (8) _______ you can have a musical experience by imagining the sound of a piece of music, then you think (9) _______ can exist without sound. But most musical experiences involve producing or (10) _______ to physical characteristics of sound such as pitch and timbre (quality comparable to texture or color in sight).
 Is the tape-recorded sound of a large metal-stamping machine music? Are 4 and 33 seconds of silence music? Is the activity of reading a list of hundreds of seemingly unrelated objects, activities, and states of mind music? Each of these "works" as well as many other sounds (or nonsounds), has been copyrighted as a musical composition, performed, and recorded in the 20th century. One of the legacies of 20 ^th-century music is to have blurred the definition of music as never before.