The purpose of this paper is to demonstrate the potential for generating interesting aggregate data on certain aspect of the lives of thousands of composers, and indeed other creative groups, from large on-line dictionaries and to be able to do so relatively quickly. A purpose-built java application that automatically extracts and processes information was developed to generate data on the birth location, occupations and importance (using word count methods) of over 12,000 composers over six centuries. Quantitative measures of the relative importance of different types of music and of the different music instruments over the centuries were also generated. Finally quantitative indicators of the importance of different cities over the different centuries in the lives of these composers are constructed. A range of interesting findings emerge in relation to all of these aspects of the lives of composers, which might provide insight and productive lines of enquiry for further work as to why certain composers were so successful in different historical periods.