6. The database constructing apparatus as claimed in claim 1 , wherein: the storage device also stores a music title database having a multiplicity of music titles stored therein, and the processor is programmed to refer to the music title database to not only extract the word usable as a music-piece-related search word from among information being provided by the accessed site but also extract a music title from among the music titles stored in the music title database, to thereby collect the extracted word, usable as a music-piece-related search word, in association with the extracted music title.
6. The database constructing apparatus as claimed in claim 1 , wherein: the storage device also stores a music title database having a multiplicity of music titles stored therein, and the processor is programmed to refer to the music title database to not only extract the word usable as a music-piece-related search word from among information being provided by the accessed site but also extract a music title from among the music titles stored in the music title database, to thereby collect the extracted word, usable as a music-piece-related search word, in association with the extracted music title. 7. The database constructing apparatus as claimed in claim 6 , wherein: if the extracted music title is already registered in the list of the database, the processor is programmed to additionally register, into the list of the database, the word collected in association with the extracted music title, and if the extracted music title is not yet registered in the list of the database, the processor is programmed to newly register the extracted music title into the list of the database and register the word, collected in association with the extracted music title, into the list of the database.