Classification and use of classifications in searching and retrieval of information

A method and apparatus are provided for classification of information and using the classification information in search and retrieval of information. In one embodiment, musical compositions having various highly subjective characteristics and features are classified according to a schema of objective attributes that are associated with the characteristics and features. Categorizers carry out the classification and create and store attribute information in a database. A search and retrieval system can receive information that characterizes the features of a desired composition and can locate a matching composition. As a result, information having subjective characteristics, such as musical compositions, may be compared and similar musical compositions can be located.