Erbarm dich mein, o Herre Gott (BWV 721)

On the website AllOfBach there is a magnificent recording of this piece by Leo van Doeselaar, played on the organ of the St Martini in Groningen. He uses only the fabulous Holfluit of the Bovenwerk and the tremulant. The result is magical. Hear for yourself: https://www.bachvereniging.nl/en/bwv/bwv-721/

When I first heard of the upcoming sample set of this organ I immediately knew I would want to try that registration for this piece myself and try and reach that magical effect.

And while I am not Leo van Doeselaar, acoustically the result in my playing room is even more magical than in the video. The sample set gives a very strong impression of being in the church and listening to the organ. The four perspectives are a bit overwhelming at first, but also give the opportunity to finetune the sound impression to your liking. I decided to not try and emulate the sound of van Doeselaar's recording and instead search for a mix that works good in my playing room. I settled on Diffuse 64, Distant and Rear both 128 while playing and made the recording uploaded here with the same setting.

About the composition, I hardly need to tell how unusual it is in Bach's oeuvre. No complicated counterpoint, just the choral melody in the upper voice and an accompaniment in repeated semiquaver chords. I always thought it a pedaliter piece, so I was a bit surprised to hear van Doeselaar play it manualiter. Looking up the manuscript however shows that it is notated on two staves. The preceding piece and the one that follows it in the manuscript are both notated on three staves. And while that is not proof, it is a strong indication that indeed this composition was meant manualiter.

Although I could easily have downloaded this piece from IMSLP, I transcribed my own score from the manuscript. Such a well known piece is hardly the subject of my website, so I did not publish it. However, if there is enough interest in it, I can publish it anyway. Just let me know.