Chiptune, Fugue, Pure Music
chiptune (aka 8-bit music) is a sound style of music from arcade video games of the 1980s. The characteristics is simple synthesized sound, back then due to technological limitations.
However, somehow i love chiptune, because they capture the music itself, without the complex sound from musical instrument. In a sense, it's pure music. (“pure music” in music theory is composition that focuses on the notes combination itself, not sound. (though, few seconds of web search i didn't find the term, for some reason. Maybe i got the term wrong.))
In fact, i always wanted to have a piano such that each key produces a simple beep sound of the right frequency, or a slightly modified pure tone with the right ADSR envelope (so the sound isn't jarring to the ear as pure tones tend to be). This would be great when playing Bach's music, in particular, his fugues, e.g. Well-tempered clavier. See:
8-Bit Liszt, Transcendental Etude #1
8-bit Liszt, Hungarian Rhapsody #2
Here's a fantastic 8-bit version of Liszt's famous song.