Canvas-based UI with visualization options. Note: Spectrum/EQ visualizations disabled for IE (too slow.) Data is not currently available under HTML5.
You can also show FPS or customize the UI, or see the hi-fi version. Check the basic template for a minimal code example; also see the default 360° UI.
Artist thank-yous: "Blue Belle Lament" courtesy of Adrian Glynn. "I Tried" and "People Asking" courtesy of SonReal.
SoundManager 2 project page (not an MP3 link)