Tunes that soothe

Zookeepers in Croatia have found a way to treat an elephant's depression with classical music. The elephant (Suma) began showing symptoms of depression (stopped eating and co-operating, failing health) after her long-time companion passed away a few months ago. Nothing could perk her up, until a concert of classical music was held on zoo grounds, not far from the elephant. As soon as Suma heard the musicians warming up, she became excited. During the concert she placed her head up against the fence, closed her eyes and listened motionlessly for the duration of the performance. Her behaviour and health was much improved afterwards. Zookeepers quickly installed speakers in the elephant area and now play classical tunes daily. Suma is doing better and seems to prefer Mozart, but others are acceptable as well.

I've heard of classical music's ability to calm the mind and soothe the soul, and that it's good to play to fetuses and babies. I also know that when I try to listen to it (except for very few specific pieces) it irritates me, while some non-classical types of music have a beneficial effect on me. So, are these supposed health benefits exclusive to classical music, or can any music that one enjoys have a positive effect? In other words, is it just a matter of whatever works for you, or is there something in the pitch and frequency of classical music that's good for all of us on a molecular level, including other species? I've heard that certain noise frequencies have been used by the military to bring about upset stomachs and other illneses in the ranks of their enemies, thus affecting their fighting ability. I think they played jazz.