Sheet music for piano and other instruments. We 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 these sites:

• Mario Piano Sheet Music - Authentic sheet music for Super Mario Bros (1985). Accurate transcription and optimized piano fingering by Joseph Karam.
• Video Game Sheet Music
• The Blindfolded Pianist