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Sine Wave A 440 Hz Concert Pitch for Ten Hours
Stop your brain from overthinking. You don't need an app. Ten hour Sine wave with no overtones which is called pure as it is only the fundamental frequency.
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A tribute from FKJ to his fans. Places you can see: Palawan, New York, Los Angeles, Paris, Ho Chi Minh , Nice, Shanghai, Colorado, Alpes, San Diego, Tokyo, Montreux, Oléron, Mumbai, Tainan, Palm Springs, Hong Kong, Bangkok, Vancouver, San Francisco, Mindoro, Saint Petersburg, Hyères, Phu Quoc, Amsterdam, Santa Barbara.