Nothing sounds quite like an ice cream van, and this post on EM411 left me wondering how they work. This is what I found: 1) " Early models consisted of a hand tuned Swiss musical movement (like a music box) fitted with a magnetic pick up and the amplifiers used radio-type valves. In 1958 reliable transistors came on to the market and efficient amplifiers were built to work directly of the vehicle's battery." (from here)
2) British vans traditionally use 'Grampian Horn' loudspeakers (which cost about £60), pointed down at the road to disperse the sound.
3) Modern chimes, like the Micro Miniatures Harmony 64, have dozens of melodies burnt onto a chip, and can play 3-note harmonies, and have a built-in 37.5 watt amplifier to drive the horn. It costs about £220.4) Today, there are very few companies still making ice cream van chimes. Micro Minatures are based in Staffordshire, while Magic Box are based in Jacksonville, Florida, where they sell ice cream all year round. Their product is a $100, 3 tune box with an 8 watt amp, perfect for neighbourhoods where loud vans cause complaints.
5) Disappointingly, nobody has created a VST ice cream van simulator.