After a brief tour postponement due to doctor's orders, Taylor Swift resumed her Speak Now world tour last Thursday (July 14) in Canada, with sold-out shows in Montreal and Toronto. In the spirit of musical camaraderie, Taylor paid respect to the one of the Great White North's most famous music exports, busting out a cover of Justin Bieber's 'Baby.' [Watch a fan video of the performance below.]

How did the Canadian tween singing sensation respond to Taylor's approving nod? By taking to his official Twitter account, of course! Justin tweeted, "Heard you sang BABY at your concert in TO. thank u for the love... might have to come by and stop in on a show."

Taylor has also been spotted with noticeable script written down her left arm during recent concerts. The self-applied Sharpie art turned out to be an homage to inspirational song lyrics, taken from pop hits by artists including Andy Grammer and Justin's girlfriend, Selena Gomez.