The conference was chaired by Pr. Keiji Hirata (Future University Hakodate, Japan) and Pr. Satoshi Tojo (JAIST, Japan) and co-organized by six local institutions, i.e. Future University Hakodate, JAIST, Nihon University, RIKEN, University of Tsukuba, Tokyo University of Science in collaboration with the Laboratory PRISM (``Perception, Representations, Image, Sound, Music''), Marseilles, France. As for previous CMMR gatherings there was also a music programme that was chaired by Assoc. Prof. Shintaro Imai (Kunitachi College of Music, Japan). The seven scientific sessions that took place during the conference dealt with both traditional CMMR topics such as music information retrieval, audio signal processing and music analysis, together with more recent topics linked to interactive systems for music and IA related approaches. Three internationally renowned keynote speakers were also invited to the conference. Shuji Hashimoto, Professor Emeritus and Research Advisor, Waseda University gave a lecture on ``Music in the AI era''. Tadahiro Taniguchi, Professor, College of Information Science and Engineering, Ritsumeikan University gave a lecture on ``Generative Models for Symbol Emergence based on Real-World Sensory-motor Information and Communication''. Gaëtan Hadjeres, Sony CSL Paris Music Team, gave a lecture on ``Developing Artist-centric Technology''. The videos of the paper (and music) programme are available at the conference website (https://www.cmmr2021.gttm.jp/).