"MIDITrail" is a MIDI player which provides 3D visualization of MIDI datasets. You can enjoy not only listening but also viewing. MIDITrail supports SMF format 0/1, and multiple MIDI ports. MIDITrail is available for Windows, Mac OS X and iOS.
MIDI visualizer provides a nicely animated rendering of MIDI music that's easily configured through a sleek, on-screen setting ...
Euphony is a MIDI player and visualizer for the web that uses WebGL for rendering.
Libraries: three.js - JavaScript 3D library ...
With this program you can listen to your own MIDI files (or play live) while viewing these visualizations:
Original bar-graph ...