SOPP476: Playing in churches with very resonant acoustics

This question was sent by James. And he writes: Dear Vidas, Forgive me emailing you again so soon, but I have recently been to two recitals by world—famous organists that were very disappointing. Reason? Playing in churches with very resonant acoustics which turned the music into a mere muddle of sound. I played one of those organs today (see attached) similar acoustics and layout to St John's Vilnius (a loud final chord took 6 seconds to be inaudible), with an attached console in the west gallery. Playing for my own enjoyment, I played at my normal speed and it sounded fine—the resonance wasn't so apparent in the gallery. But I know in the body of the church it would have sounded a mess. Are there any simple rules for judging speed, legato etc in these circumstances? Maybe this will be of interest to others. Best wishes, James PS am still working on "Memento" - a challenge, but the miracle WILL happen!