Aeolian harp

They were very popular as household instruments during the Romantic Era[?], but are still being hand-crafted today. Some are now made in the form of monumental metal sculptures located on the roof of a building or a windy hilltop.

The traditional aeolian harp is essentially a wooden box including a sound board[?], with strings stretched lengthwise across two bridges. It is placed in a slightly opened window where the wind can blow across the strings to produce sounds. The strings can be made of different materials (or thicknesses) and all be tuned to the same note, or identical strings can be tuned to different notes.

The sound is random, depending on the strength of the wind passing over the strings, and can range from a barely audible hum to a loud scream. If the strings are tuned to different notes, sometimes only one tone is heard and sometimes chords.

Aeolian harps are featured in at least two Romantic-era poems, The Aeolian Harp and Dejection, an Ode, both by Samuel Taylor Coleridge.

External links:

The Æolian Harp (http://www.mindspring.com/~mtiefert/poetry/coleridgeAeolianHarp)