Spotify loves to tinker, and now it’s tinkering—again—with song lyrics for free users. After making real-time song lyrics almost entirely exclusive to paid users earlier this year, Spotify has changed its tune, telling Engadget that it is “expanding lyrics availability for Spotify Free users.” Spotify turned lyrics into a Spotify Premium-only feature back in May, restricting free users to just three songs a month with real-time lyrics. Spotify first began testing song lyric restrictions on free users last fall. This news story is part of TechHive’s in-depth coverage of the best streaming music…