"Mario Paint" is also the title of a fairly rare album by a collective of Japanese musicians known as The Electric Family, released in 1995 by the UK based Irdial record label. The album, as its name suggests, is composed entirely with the sequencer in the Mario Paint game for the Super Famicom.
The majority of the eight untitled tracks are really playful and lighthearted which I think clearly reflects the medium in which the songs were created -- when you're composing a song using mushrooms, invincibility stars, and fire flowers as notes, I imagine it's difficult to create music that takes itself seriously.
I bought the album for the sheer novelty of it, not expecting much, but I found it really delightful to listen to; it never fails to put a smile on my face. If you can find it, I highly recommend it.
Some info about the recording gear from the liner notes:
The sole machine used on these recordings was a Nintendo Super Famicom, running the Mario Paint music sequencer. Each track was recorded in 4 days, at Kley Sound. The Super Famicom was running through an RCA NTSC VHS recorder, Konami Game Selector and a Sony F319R Spontaneous Twin Drive Super Legato Linear amplifier. The NTSC TV was a Toshiba Blackstripe. The mastering recorder was a Struder B16 in console. The tape was Ampex 456.