Recently, I read an article about outdoor billboard advertising that would follow the line of sight of passers by. The really cool thing about this technology was that it was equipped with a camera, and facial (expression) recognition software. The add would switch its content in response to the facial expression of the passer by. Changing to a different ad, or tactic, if the expression was negative; and offering more info if the expression is positive. Sending messages to personal electronics was also a factor. The ad would search out blue-tooth connectivity and would send ads to devices with happy, intrigued, customers.
In relation to music advertising. A record store, an elevator, or really anywhere applicable, could alter the music it is turning out in relation to the reaction of consumers. This technology could also provide incredible research into what types of music, or techniques, are popular. The selection of music could be done on a consensus basis, of all the persons in the camera sight line; or individually to customers personal electronics.
The possibilities for personal advertising and market research are very exciting.