'. . . Astronomers say they have heard the sound of a black hole singing. And what it is singing, and perhaps has been singing for more than two billion years, they say, is B flat -- a B flat 57 octaves lower than middle C.
The ''notes'' appear as pressure waves roiling and spreading as a result of outbursts from a supermassive black hole through a hot thin gas that fills the Perseus cluster of galaxies, 250 million light-years distant. They are 30,000 light-years across and have a period of oscillation of 10 million years. By comparison, the deepest, lowest notes that humans can hear have a period of about one-twentieth of a second.
The black hole is playing ''the lowest note in the universe,'' said Dr. Andrew Fabian, an X-ray astronomer at the Institute for Astronomy at Cambridge University in England. . . '
Another site referred to this song as our universe's "longest symphony." Yet another referred to the idea that healing properties are inherent in the vibrations emitted by the note B-flat.