(Piano Solo Songbook). Canadian composer, pianist and songwriter The Theorist (a.k.a. Henderson Nguyen), rose to fame as a musical sensation on YouTube and now performs the world over. This collection features The Theorist's take on 17 popular songs for piano solo: All of Me * Crazy in Love * Fake Love * Lay Me Down * Shape of You * Thinking Out Loud * Versace on the Floor * Young and Beautiful * and more.