The "Matrix" is a Freesound Music flagship project that presents 88 Animated Sounds in one browser window. You will need a very strong Internet connection or lots of patience to come comfortably through the first time downloading period. Don't forget: Usually each sound is packed with some neighbored sounds so that you are in fact downloading several hundreds of sounds. However, next time, the complete matrix is already waiting for you in the browser's cache.
Once you are done, you will set the browser window to full-screen (F11) and enjoy a huge Play Console containing various groups of sounds, some of them embedded in the Web Songs project that you can launch from there as well, others to be used more independently or in free conjunction to the Web Songs arrangements.
The Matrix sounds are ordered according to FleX-Layers in the following order: two rows Xpressions, two rows Layers, two rows Events, and two rows Figures.