@article{ToivanenJAVVT:CS2018, title = {Towards Transformational Creation of Novel Songs}, author = {Jukka M. Toivanen and Matti J\"arvisalo and Olli Alm and Dan Ventura and Martti Vainio and Hannu Toivonen}, journal = {Connection Science}, volume = {31}, number = {1}, pages = {4--32}, year = {2019}, } Abstract: We study transformational computational creativity in the context of writing songs and describe an implemented system that is able to modify its own goals and operation. With this, we contribute to three aspects of computational creativity and song generation: (1) Application-wise, songs are an interesting and challenging target for creativity, as they require the production of complementary music and lyrics. (2) Technically, we approach the problem of creativity and song generation using constraint programming. We show how constraints can be used declaratively to define a search space of songs so that a standard constraint solver can then be used to generate songs. (3) Conceptually, we describe a concrete architecture for transformational creativity where the creative (song writing) system has some responsibility for setting its own search space and goals. In the proposed architecture, a meta-level control component does this transparently by manipulating the constraints at runtime based on self-reflection of the system. Empirical experiments suggest the system is able to create songs according to its own taste.