Studies indicate that music can have profound physical and psychological effects not only on people but also on animals and plants.

Jennifer Copley writes as follows:

Research into the effects of music on behavior, intelligence, learning, pain tolerance and health have generated a number of interesting findings. This article describes the results of some of the more intriguing experiments and studies.
Music, Mice and Madness

A student named David Merrill devised an experiment to discover how music would affect the ability of mice to learn new things. Merrill had one group of mice listen to classical music 24 hours a day and another to heavy metal music. He then timed the mice as they ran through mazes to see if the music affected their speed of learning. Unfortunately, he had to cut the first experiment short because the heavy metal mice all killed one another.

In a second experiment, mice that listened to Mozart for 10 hours a day dramatically improved their maze-solving abilities, while the heavy metal mice actually became worse at solving mazes than they had been at the beginning of the experiment.