Music is rich in information that can be processed along different dimensions. Four types of musical dimensions that correspond to different levels of perception and cognition are discussed: (1) the dimension of sound, (2) the dimensions of melody, rhythm, and harmony, (3) the dimension of compositional structure, and (4) the dimension of compositional content. These psychological dimensions of music, and the psychological activities relevant to these dimensions, depend highly on context and on schema. Thus the four types of musical dimensions are not independent, but interact with each other. Some evidence from new research on the sense of pitch deviation, the sense of fitness of timbre to melody, and similarity and octave judgments referring to the problem of wording are discussed.