Binaural Beats | Warm Pink Noise | 108 - 162 Hz | Slowly Oscillating Deep Meditation Noise | 3 Hours 

Two sine waves, oscillating in amplitude at different rates. Together they produce a perfect fifth. Layered with pink noise to fill up the empty space. Good for meditation, focus while working, while trying to sleep.
I recommend you use headphones, unless you're trying to sleep
Don't listen while driving or operating heavy machinery.