Most people know of the visualisations in Winamp, Windows Media Player, XMMS and similar programs. They show hypnotising and colourful effects that react to the music. There's one disadvantage: they only work on a computer. This is something we're about to change! Using a powerful ARM chip and an old GSM display, in this article we'll be making a standalone version. With the right ‘plug-in’ it can also function as a real-time spectrum analyser.