“…Among the various subtopics in content-based MIR, automatic chord estimation has received a considerable and sustained attention since its inception (Fujishima, 1999). Not only it is a very interesting and challenging problem, but also it has many applications in high-level tasks such as cover song identification (Marsík et al, 2017), genre classification (Pereira and Silla, 2017) or automatic accompaniment (Ojima et al, 2017). Also, there is a high demand on chord-based representations by users in the music community, as illustrated by the popularity of websites such as Ultimate Guitar 1 .…”