Open Air was an interactive artwork by Rafael Lozano-Hemmer, commissioned by the Association for Public Art. The piece allowed participants’ voices to transform the sky over Philadelphia.

Using this website you could record a voice message and listen and rate other entries. The higher rated messages were played-back over the Benjamin Franklin Parkway using 24 powerful robotic searchlights that reacted, both in brightness and position, to your voice’s frequency and volume.

Every night from September 20 to October 14 the project made huge light formations, visible from 10 miles away, that were automatically controlled by your voice. Follow this link for all the details, or see the project videos and photos.

If you were in Philadelphia, you could participate using a free iPhone app, which gave your message a high priority and pointed the lights toward you when your message was in the sky.
……
During the project run, 63,000 people visited this web site, from 92 countries, who left close to 6,000 messages in over 20 languages. Personalized web pages were made for each message. You may still listen to them and record your own. You can also read the final press release.