Comment 2 for bug 916841

Same on precise since upgrade to elementary-icons >3.0

for now I'm just using the "multimedia-audio-player.svg" icon

To get the same do this in console but be aware, that this might get overwritten (actually it most certainly will) in a future upgrade.

sudo su -
cd /usr/share/icons/elementary/apps/
for i in *; do cp -v ./$i/multimedia-audio-player.svg ./$i/beatbox.svg; done