J. S. Bach - Chorale Prelude "Erbarm dich mein, o Herre Gott" BWV721

This piece appears as strikingly simple arrangement by Bach. But this simplicity is combined with perfect harmony. The Unda Maris in the solo division - one of the most beautiful stops of the instrument - mystically carries the cantus firmus of the chorale.
I got inspired by Juan de la Rubia's recording at the Metzler organ in the Poblet monastery. Here, I decided to apply a slightly faster pace.