It would be interesting to add one or two hashtags to every tweet to identify the song being tweeted. For example:

They bought and sold you
#WhileMyGuitarGentlyWeeps #TheBeatles

This would require editing the lyrics.txt file to add a hashtag to every single line.
Another approach could be separate the lyrics in individual files for every song and randomly select a file and a line from a file to create the tweet and add the hashtag.