The YouTube community and fans were shocked to learn of the sudden passing of Christina Grimmie on Saturday. The 22-year-old singer was shot dead by a gunman while signing autographs for fans after a show in Florida. Grimmie's brother tackled the gunman after he opened fire, and during the struggle the gunman shot and killed himself. While many became familiar with the young musician through her appearances on The Voice, Grimmie became an inspiration and familiar voice to many through her various covers of pop songs on her YouTube channel, which she started in 2009 at the age of 15. From Adele to Justin Bieber and Rihanna, Grimmie often took requests from fans and performed the stripped-down versions alone with her piano, captured in a single shot and single take. Remembering her outstanding ability to put her own take on any song, here are some of Grimmie's stand-out YouTube covers. Editor's note: The author of this post briefly worked with Christina Grimmie in 2011 as a post production audio editor. Have something to add to this story? Share it in the comments. TopicsYouTube