The RapidAPI blog post evaluates and ranks the top free music data APIs available to developers in 2021, highlighting eight standout options: Shazam, TheAudioDB, Deezer, Mourits Lyrics, iTunes, Spotify, LastFM, and an API for 30,000 radio stations and music charts. Each API offers unique functionalities, such as song identification, access to extensive music metadata, playlist creation, and retrieval of song lyrics. The blog emphasizes the diverse applications of these APIs, from enhancing apps with music recognition capabilities to providing comprehensive audio metadata and facilitating music streaming. These APIs are accessible through RapidAPI's platform, which supports multiple programming languages and offers developers a centralized hub for exploring and integrating APIs.