O Haupt voll Blut und Wunden

Carl Gustav Flügel (1812-1900) was a German composer and organist.
There is an extensive English Wikipedia page about his life. Since he died at 88, he almost lived through the entiry 19th century. So many developments of the 19th century, not only the musical ones, reflected in his compositions, from classical to Wagnerian. He often used the classical strict forms like sonatas, canons, fugues. His Präludienbuch contains many gems for organ. This piece here is one of them. The tune is the same as 'Ach Herr mich armen Sünder' and 'Herzlich tut mich verlangen'. It is a short prelude on the chorale, it only uses three phrases of the hymn. So probably perfect for use in a service.