Over the last decade, music-streaming services have grown dramatically. Pandora, one company in the field, has pioneered and popularized streaming music by successfully deploying the Music Genome Project  (https://www.pandora.com/about/mgp) based on human-annotated content analysis. Another company, Spotify, has a catalog of over 40 million songs and over 180 million users as of mid-2018 (https://press.spotify.com/us/about/), making it a leading music service provider worldwide. Giant technology companies such as Apple, Google, and Amazon have also been strengthening their music service platforms. Furthermore, artificial intelligence speakers, such as Amazon Echo, are gaining popularity, providing listeners with a new and easily accessible way to listen to music.