Music Classification: Beyond Supervised Learning, Towards Real-world Applications Book

This is a web book written for a tutorial session of the 22nd International Society for Music Information Retrieval Conference, Nov 8-12, 2021 in an online format. The ISMIR conference is the world’s leading research forum on processing, searching, organising and accessing music-related data.

The scope

The history of music classification dates back to at least 1996 [WBKW96]. The motivation of music classification remains the same since then.

The rapid increase in speed and capacity of computers and networks has allowed the inclusion of audio as a data type in many modern computer applications.

It was further clarified in [TC02].

..gaining importance as a way to structure and organize the increasingly large numbers of music files available digitally...

In this book, we focus on the more modern history of music classification since the popularization of deep learning in mid 2010s. Please refer to [FLTZ10] for the earlier progress in 2000s, which was mainly the design of audio features and adoption of classifiers as well as the birth of many music classification problems. [NCL+18] includes detailed discussion of the transition to deep learning approaches. There also exist other existing tutorials, [SLBock20] and [CFCS17b], that include more general MIR topics with a special focus on deep learning.


Lower the barrier: As deep learning emerges, music classification research has entered a new phase, and many data-driven approaches have been proposed to solve the problem. However, researchers sometimes use jargon in various ways. Also, some implementation details and evaluation methods are ambiguously described in the papers, blocking access to the information without personal contact. These are tremendous obstacles when new researchers want to dive into this fascinating research area. Through this book, we would like to lower the barrier for newcomers and reduce miscommunication between researchers by sharing the secrets.

Cope with data issue: Another issue that we are facing under the deep learning era is the exhaustion of labeled data. Labeling musical attributes requires strong domain knowledge and a significant amount of time for listening; hence expensive. Because of this, deep learning researchers started actively utilizing large-scale unlabeled data. This book introduces the recent advances in semi- and self-supervised learning that enables music classification models to step further beyond supervised learning.

Narrow the gap: Music classification has been applied to solve real-world problems successfully. However, some important procedures and considerations for real-world applications are rarely discussed as research topics. In this book, based on the various industry experiences of the authors, we try our best to raise awareness of these questions and provide answers and perspectives. We hope this helps academia and industries harmonize better together.

About the authors


Minz Won is a Ph.D candidate at the Music Technology Group (MTG) of Universitat Pompeu Fabra in Barcelona, Spain. His research focus is music representation learning. Along with his academic career, he has put his knowledge into practice with industry internships at Kakao Corp., Naver Corp., Pandora, Adobe, and he recently joined ByteDance as a research scientist. He contributed to the winning entry in the WWW 2018 Challenge: Learning to Recognize Musical Genre.


Janne Spijkervet graduated from the University of Amsterdam in 2021 with her Master’s thesis titled “Contrastive Learning of Musical Representations”. The paper with the same title was published in 2020 on self-supervised learning on raw audio in music tagging. She has started at ByteDance as a research scientist (2020 - present), developing generative models for music creation. She is also a songwriter and music producer, and explores the design and use of machine learning technology in her music.


Keunwoo Choi is a senior research scientist at ByteDance, developing machine learning products for music recommendation and discovery. He received a Ph.D degree from Queen Mary University of London (c4dm) in 2018. As a researcher, he also has been working at Spotify (2018 - 2020) and several other music companies as well as open-source projects such as Kapre, librosa, and torchaudio. He also writes some music.


We use Jupyter Book[Com20], Librosa 0.8.1[MRL+15] [MMM+21], Pytorch[PGM+19], Torchaudio[YHN+21], Matplotlib[Hun07], and Numpy[HMvdW+20].

Citing this book

    Author = {Won, Minz and Spijkervet, Janne and Choi, Keunwoo},
    Month = Nov.,
    Publisher = {},
    Title = {Music Classification: Beyond Supervised Learning, Towards Real-world Applications},
    Year = 2021,
    Url = {},
    doi = {10.5281/zenodo.5703779}


  • You can download a pdf of this book from zenodo. If the pdf is not up-to-date, you can build it by yourself on your local machine.