This surprisingly clean and clear recording was made using a vintage cassette recorder, in Japan. Play time is nearly half an hour!
The video features fade to black, blanking the screen after 10 seconds. The feature causes less drain on battery powered devices and causes no annoyance or distraction if used as a sleep aid.

Recorded near Tokyo, bush warblers (Horornis diphone) are plentiful in the surrounding areas. They are more often heard than seen, due to their small size and brown colouration.

Such recordings are superb for use while studying, researching, relaxing, unwinding, or as sleep aids.

Check out 'Lord of the Hertz' on Bandcamp, for similar content.
https://lordofthehertz.bandcamp.com/
Original thumbnail picture by Alpsdake from the Wikipedia article on bush warblers. The same public license applies for it's use in this video.