|Firefox 3.5 logo|
According to the Mozilla Blog, "...developers can read and write raw audio data within the browser, presenting audio information in completely new ways that could allow, for example, for people to visually experience a speech or a song through Firefox."
The blog post has a video (which just has a music playing, no dialogue) that shows some of the neat ways we'll be able to visually interpret music in the new Firefox. There are many ways developers can display data and visualize sound.
Try out the Firefox 4 Beta here.