In contrast to Oldenburg’s concept of «library – the “third place”» the article presents its role as the «second place», i.e. the place for study and work, on the examples of music and art schools libraries, (music schools/CAS) of St. Petersburg. These establishments meet the specific needs of library users (students and teachers) that occur in the process of educational activities on pre-service programs in various types of art. The peculiarity of these libraries permit them to preserve their own niche in the general library and information space and in each concrete institution of additional education. The article examines social functions, goals and tasks of DMSH/DSHI libraries, their normative-legislative regulations, financial and acquisition questions, work of referencesearch apparatus, forms of servicing users. Possible ways of their development are designated: creation of the special Model standard; transformation of libraries into educational information centers on art in the educational environment of schools with the appropriate technical and technological equipment and the Internet access; active mastering of social networks. All this will allow DMSH/DSHI libraries to develop and implement additional forms of service.