Why do some people hang empty glass bottles from trees?

Hanging glass bottles from trees is believed to create a musical effect when the wind blows through them. Bottles of similar sizes that produce harmonically pleasing tones when struck are preferred and hung so air may circulate through them easily. This practice became particularly common during COVID-19 lockdowns as a creative outlet of artistic expression and a source of auditory interest on daily walks. Hanging such glass bottles could serve to improve one's mood, inspire, or provide enjoyment to themselves and those experiencing their surroundings.