Watching visualizations of music can be a rewarding wat to understand a piece on another level. Some of these are more successful than others. Of course, the simplest would be just watching a musician play.
The video Glenn Gould made of his second version of the Goldberg Variations is just stunning. Watch him play the last four variations (26-30) and the final aria.
Next, following along with the score as a musician plays is enlightening -- for instance, turning the pages for a pianist. If you can't do that, you can follow the score of John Coltrane's mighty Giant Steps.
Finally, Stephen Malinowski has made music animations for years, using MIDI files to control an application with several visualization patterns. The bar graph version is the simplest for me to follow, and it's pretty effective when used in conjunction with a following score and video of the pianist's hands playing.
