Want You Gone (Portal 2 End Credits) - Piano + Lyrics 

Try the interactive tutorial, or download the sheet music here: musescore.com/...
This is "Want You Gone" from the end credits of Portal 2. It is sung by GLaDOS (Ellen McLain) after she decides to let Chell (the player) return to the surface and escape Aperture Science's Enrichment Center. I hope you enjoy his Piano and lyric arrangement!