1. A sound data processing device for, for each of a plurality of performance parts, searching through a database, storing therein part performance data of a plurality of performance parts, for particular part performance data, the part performance data for each of the performance parts including a sound generation pattern and tone data corresponding to the sound generation pattern, said sound data processing device comprising: a query acquisition section configured to acquire a query pattern indicative of a sound generation pattern to be made an object of search; a search section configured to search through the database for part performance data including a sound generation pattern matching the query pattern; and a search instruction section configured to, in response to a user's operation, identify one part performance data from among searched-out part performance data from the database and instruct said search section to perform a search using, as a new query pattern, the sound generation pattern of the identified performance data.