Might be of interest a system that I've been used wich is: I've built a Box where a button can be pressed in case the visitor wants music. In the same box there is a small written introdution to the theme. The rooms, wich in general are small/medium size there are 4 speakers wich give a good ambience to the room. Inside the box I have adapted an auto cassete player connected to a watch-switch wich after 1, 2, 5, 10 minuts (depends on pre regulation) automaticly switches off. Sound quality is acceptable and the system has been working perfectly for more than 2 monthes now. Emanuel