That doesn't surprise me in the least. I know they've done study after study with plants and music and invariably plants grow toward speakers playing classical music and grow away from pop, heavy metal, and rap.

Classical, I think, calms humans down too. I did a little survey of my own in my classroom one year and one week I played rock music while they worked and the next I played classical (wow did they complain), and their scores increased the week I played classical and they were better behaved. I don't know if that was because the music calmed them down or they hated it so much they ignored it and did their work!