A Chorale Prelude is a short instrumental composition for organ, which uses a chorale tune as a basis. It is liturgical in nature (more specifically Protestant Christian), though its specific function in the church service is still debated by scholars: it may have been used to introduce the melody of the hymn about to be sung by the congregation. In any case the Chorale Prelude enjoyed a great success as an independent genre, with Dietrich Buxtehude and Johann Sebastian Bach writing more than 90 pieces in this form. Some romantic composers revived Chorale Prelude, such as Johannes Brahms.