lol. Theres an episode of mythbusters that is about this. They grew vegetables on the roof of their building and play classical music and talk lovingly to the plants and in another green house they do nothing and the 3rd greenhouse they were blasting heavy metal yelling and screaming and cursing at the plants. The heavy metal veggies were the biggest and best tasting. So maybe theres something to it.
I know a fan makes the stem stronger because it disturbes it. Maybe lightly knocking your plant and playing loud fast music creates an unstable enviornment where the plant has to fend for its self more whilist being controlled and never really damaged.
Loud music creates tons of kinetic energy which would vibrate your plants by the roots themselves. (just dont get a noise complaint)