The speaker tubes. Supplied by TTI (Tube Technology Industries). We opened up cheap PC Desktop audio monitors, and extended the connection between speaker and circuit board. A basic hack, but effective (and cheap!). Although not visible here, some of the tubes contained led lights each powered with a 3V battery throwie style (a convenient way of powering led's, not the most environmentally friendly way of doing things, but in this case a compromise better than building circuits and running several meters of cable).