I just recently stumbled upon this excellent video of Jim Carrey performing and recording a cover of the Beatles tune I Am the Walrus. After some minor digging I discovered that this recording was part of a 1998 compilation album production called, In My Life (George Martin Album). Several well-known artists besides Carrey worked on covers of beloved Beatles tunes, artists such as Robin Williams, Bobby McFerrin, Goldie Hawn, Céline Dion, Vanessa-Mae, Phil Collins, and even Sean Connery.
The 1998 album was compiled and produced by George Martin, and is nearly entirely comprised of the songs which he originally produced with and for The Beatles.
Sir George Henry Martin CBE (born 3 January 1926) is an English record producer, arranger, composer, conductor, audio engineer and musician. He is sometimes referred to as “the Fifth Beatle”—a title that he has described as “nonsense”—in reference to his extensive involvement on each of The Beatles’ original albums. –(source)
Enjoy this amazing performance by Jim Carrey!