Johann Sebastian Bach's Orgelbüchlein (Little Organ Book) contains chorale preludes for the church year written during composer's service at Weimar (1708 - 17). Such pieces, combining learned counterpoint with expressive meditation on the chorale on which the prelude is based, were new in conception. As organist at Weimar, Bach was charged with providing a harmonic underpinning for use by those assembled at church services who sang the Lutheran chorale tunes chosen for each day. Bach wrote out many of these harmonizations, in part as instruction for younger composers. They are still used for this purpose.

Bach's Orgelbüchlein was essentially complete by 1716. Only the fragment "O Traurigkeit" and the chorale prelude "Helft mir Gottes Güte preisen," BWV 613, were added later. "Complete" is used with some reservation here, because Bach originally projected 164 pieces but completed fewer than fifty. (In Bach's manuscript, pages with finished pieces alternate with blank ones intended for other chorale preludes.) These brief pieces differ from Bach's earlier chorale elaborations in that they contain only one statement of the melody and are intended to demonstrate how to accompany a chorale with contrapuntally proper figurations that support the meaning of the text.

"Ich ruf' zu dir, Herr Jesu Christ" (I call to you, Lord Jesus Christ), BWV 639, is in three parts with a clear division among the voices. In the uppermost voice we find the chorale melody, slightly decorated with mordents and dotted rhythms. The middle voice is a continuous flurry of sixteenth-note arpeggios that creates an adventurous harmonic background. The pedal insists on a constant eighth-note pulse, with many repeated notes that seem to emphasize the protagonist's entreaty to his Lord.