This thesis focuses on the design of interactive paper interfaces for supporting musical creation. Music composition has been deeply influenced by the computational power brought by computers but despite the use of software to create new sounds or work with symbolic notation, composers still use paper in their creative process. Interactive paper creates new opportunities for combining expression on paper and computation. However, designing for highly individual creative practitioners who use personal musical representations is challenging. In this thesis, I argue that composers need personal and adaptable structures on paper in which they can express and explore musical ideas. I first present three field studies (Chapter 3) with contemporar...