Few possess the vocal skill necessary to master "I Will Always Love You" by Dolly Parton, especially the version popularized by the late Whitney Houston.
Musician Marc Martel is well known for tackling the persona of Freddie Mercury, but in an acoustic performance, he switched things up with a stirring cover of Houston's version of "I Will Always Love You."
So who sang it best? Marc Martel, Whitney Houston or Dolly Parton? Never mind -- they're all incredible.