Genius is a site where users annotate songs. Contributors to the site give the lyrics of the song with explanations and examples, so that the song can be better understood.
One of the main difficulties about English music (for both native and non-native speakers) is understanding the context and all the cultural references in the song.
On Genius, users explain the hidden meaning of lyrics and give examples, so that we can learn both the meaning of the lyrics and what they refer to. The story behind the song is sometimes featured.
On Genius we can find all music genres as well and an A-Z index of artists.
Here are the annotations and lyrics for Beyoncé's Formation.
H/T to English Fluency Now