projectM is a music visualizer, a MilkDrop (plugin for Winamp) reimplementation using OpenGL for systems other than just Windows, or Winamp as another way to look at. It visualizes the audio from PulseAudio, JACK, or whatever it supports. I installed the Gentoo package media-sound/projectm-pulseaudio-2.1.0 and here is an animated GIF I made:

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjy6QlZbsH3ie4iuQNEDlhJ9zJodftKuwpkv-BCfoSrPFv-JAGr5XLzyaOb1nyZ2CQz2qAnONiUtUa_Htm91iUhn4BmWOZdHIHZElr9s44rCn1Fa05gZd405kVFjOEM0k3XqZTgpSwZ5ks/s800/projectM.gif

I don’t see any command-line options or manpages, so I guess that’s only be run and leave on the screen, like a nice screensaver. I tried to press some keys and -h, none of those has effects.

If you want to have a text-mode version for music visualization, you could try consolecandy (video I made), but I don’t recommend. projectM has much better performance and many more visual effects—called presents in projectM—even though you don’t seem to be able to choose what you want to see.

With maximized window, almost 1680x1050, it still only takes around 13-14% of CPU, it’s definitely running efficient enough and pretty for sure.

It seems to have media player plugins, like iTunes, Windows Media Player, or XMMS. It runs on Unix-like, OS X, Windows, iOS, and Android. Licensed under the LGPLv2.1.