This is a 4 part partita on this well-known melody, in the style Johann Pachelbel often uses: The harmonization of the chorale melody, then followed by a few variations.
After the last variation, one with the melody in the pedal part, there is a small pause, after which the setting on this chorale by J.S. Bach follows: a rather elaborate one, compared to the simple yet effective setting by Pachelbel.
The chorale in Pachelbel's partita is in 3/4 time.
The setting by Bach in 4/4 time.