Miku Hatsune (Hatsune Miku) is a Japanese character created by Crypton Future Media Inc as a Vocaloid, a voice synthesizer program developed by Yamaha. She was released to the public on August 31 2007, along with two demo songs using her voice. She was soon used by various music producers as the singer of their songs and developed a very large fan base, with her songs having over millions of views on both Youtube and the Japanese video sharing site, "NicoNicoDouga". Since then, she has had multiple video games (most popular being the rhythm game series, "Project Diva"). She has also appeared in multiple solo concerts (as a projection on a transparent screen) with live bands performing the instrumentals, as well as appearing at multiple music festivals. On October 8th 2014, she and her band performed on The Late Show with David Letterman. Since this, she has started holding concerts more frequently.