When I was a student at the Lithuanian Academy of Music back in 1997, together with one colleague of mine we were chosen to go to the International Summer Organ Academy and Festival „Juniores Priores Organorium Seinensis“ in Sejny, Poland (Seinai in Lithuanian) with my professor Leopoldas Digrys.
This little town, which is close to Lithuanian/Polish border, houses a Basilica with a two-manual Romantic mechanical action organ, built by the Lithuanian organ builder Jonas Garalevicius from 1907. This instrument stands behind the older, quite ornate Baroque facade, as it's often the case with older organs.
Although 17 years have passed from that summer, here's what I remember as clearly as today: this organ had an incredibly heavy action. I had played many organs ever since and most of them were mechanical but no instrument could compare to that of the action of the organ at the Basilica in Sejny (I'm sure there are even more challenging organs than this one in the world, though).
In Sejny, I played a charming Organ sonata No. 3 by Paul Hindemith, one of the most significant 20th century German composers, which is not terribly challenging piece technically but for some reason, depressing the keys felt like a torture, especially in the 3rd, faster movement.
Clearly my technique was not developed enough (although the action itself might have felt differently when the organ was new back in 1907). I remember my professor advising me to relax my hands and shoulders and use large muscle groups instead of fine fingerwork. This helped a lot.
So, if you are in a similar situation, try not to lift the fingers of the keys, relax, and breath. It's wise not to choose to play very virtuosic pieces on such an organ, if your technique isn't flawless. Improvisation always helps because when you're improvising, you're are constantly adjusting to the real situation.
A lot of people nowadays play electronic organs, older of which have a very light touch. After practicing a lot on such an instrument and suddenly given an opportunity to try a real mechanical organ (even not with a very heavy action) will present certain difficulties.
And here's is my long-term advice:
Perfect your finger technique as much as you can and you will never be in real peril when playing a mechanical organ with a heavy action.
Piano playing is good for finger technique, too. So if you have a chance to practice your organ pieces on the piano, please do it often. If you don't like practicing scales, arpeggios, chords and Hanon exercises, you can take your favorite pieces and create the exercises out of them.
[HT to Jon]
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Ricercare del quarto tuono by Adriano Banchieri (1568-1634). He was an Italian composer, music theorist, and organist of the late Renaissance-early Baroque period.
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