$ lyrics

Default player is Spotify, but the lyrics-in-terminal will auto switch if you start playing media in another player.
Press a to toggle this behaviour.

If you want to show lyrics from specific player only, then pass player name as an argument (auto switch will be toggled off).

$ lyrics {playername}

$ lyrics vlc
$ lyrics audacious
$ lyrics rhythmbox

If you don't want to keep detecting playing music and only want to get lyrics of a single song. Then use -t option

$ lyrics -t {artist} {title}

$ lyrics -t gojira silvera
$ lyrics -t 'The Rolling Stones' 'Paint It, Black'

If you want to use your own pager, then pipe the output.

$ lyrics -t Tool Sober | less