You might not think that Taylor Swift and Kendrick Lamar have a lot in common (other than being critical favorites), but this week they both proved that they are also fans of each other's music. Taylor kicked things off by posting a video of herself lip-syncing to Kendrick's "Backseat Freestyle" in response to the news that her album 1989 had gone platinum in one week (which, incidentally, also made it the first album released in 2014 to go platinum this year). Meanwhile, a clip of Kendrick singing Taylor's "Shake It Off" went viral on Tuesday after he burst out into song during an interview. "I love that song," Kendrick said after he was done singing. "I ain't playin'." Watch Taylor's rap-sync above, and check out Kendrick's singing skills below.