The Unfortunate Fate of Music MIDI File
MIDI is really a great tech, but unfortunately, it never picked up in computer.
MIDI is a standard format to record musical notes. MIDI file is tiny in size, especially great for piano music. For example, a 5 minute piano piece is only 11k bytes.
10 years ago, i'd expect by now that on each computer we have high quality sampled sound library for MIDI, so that perhaps just a 100 mega bytes you'd have entire collection of piano music in history, recorded by professionals. Not so.
Today, on the web, MIDI isn't supported by browsers.
Here's the embedded midi file: bach_wtc1_f04.mid
See also: HTML Audio Tag
The w3c has a draft standard for MIDI: http://webaudio.github.io/web-midi-api/