Sheet music for piano and other instruments. I do not know if any official sheet music exists; if it does, it would be available in Japan for sure.

Super Mario Bros.

• Main theme [pages: 1, 2, 3]
  Originally composed by: Koji Kondo
  Transcribed by: Aaron Ackerson

For more sheet music, check out Video Game Sheet Music, The Blindfolded Pianist, and Nintendo Sheet Music.