<P> The prelude is 35 bars long and consists mostly of broken chords . Below are the first four bars of the prelude: </P> <P> The prelude continues like this with different variations on harmony, and change of key . The prelude ends with a single C major chord . </P> <P> Some earlier editions of the prelude contain an extra bar between bars 22 and 23 known as the "Schwencke measure", a measure allegedly added by Christian Friedrich Gottlieb Schwencke in an attempt to correct what he or someone else erroneously deemed a "faulty" progression, even though this sort of progression was standard in Bach's music . </P> <Table> <Tr> <Td> </Td> <Td> This section needs expansion . You can help by adding to it . (October 2017) </Td> </Tr> </Table>

Bach's prelude and fugue no 1 in c major