Hertz counts vibrations per second. Concert pitch is A = 440 Hz; A = 432 Hz is about 32 cents lower, a matter of taste. The 174 to 963 Hz tones carry popular healing claims without strong scientific evidence; here they are musical colors, and Lock to signal tunes the song to your first tone layer.

Binaural beats need headphones: a slightly different tone in each ear creates a perceived beat. Research is mixed. Bands: delta 0.5 to 4 Hz (deep sleep), theta 4 to 8 (drowsy), alpha 8 to 13 (relaxed), beta 13 to 30 (alert). Isochronic pulses work on speakers. Rain, ocean and solar wind are shaped noise that masks distraction and can soften mild ringing.

Instruments of the United States and its treaty allies (NATO, Japan, South Korea, Australia, the Philippines, Thailand), each synthesized from scratch: physical string models, reeds and winds with breath noise, bell-like gongs and mallets. Respectful approximations, not recordings.

Cousto's method doubles a cosmic cycle's frequency until it is audible: the Earth day becomes 194.18 Hz, the Earth year 136.10 Hz. Poetic and musical, paired here with lydian harmony and orbiting stereo.

• Bend pad: sideways slows or speeds the tape; up or down opens or darkens the sound.
• Tilt: left or right moves the signal layers; forward softens harsh highs.
• Velocity engine: your pace sets the tempo; climbing opens the filter.
• Privacy: location and voice never leave your device.

• Extended chords and rootless voicings give the floating church-keys color.
• The lift raises the final hook a half or whole step.
• Trap soul pairs slow R&B harmony with a gliding 808 and rolling hats.
• Parade cadence uses field snare rolls, bass and tenor drums in an original pattern.

Tinnitus and hearing loss are among the most common service-connected conditions. Keep volume moderate (no more than 60% for 60 minutes is a common guide) and take breaks.