Der Freischütz, Op. 77, J. 277, is a German opera with spoken dialogue in three acts by Carl Maria von Weber with a libretto by Friedrich Kind. It premiered on 18 June 1821 at the Schauspielhaus Berlin. It is considered the first important German Romantic opera, especially in its national identity and stark emotionality. The plot is based on the German folk legend of the Freischütz and many of its tunes were inspired by German folk music. Its unearthly portrayal of the supernatural in the famous Wolf's Glen scene has been described as "the most expressive rendering of the gruesome that is to be found in a musical score".