This is a joyful and playful arrangement of the hymn tune, ST DENIO, by Phil Lehenbauer. The score for organ is available instantly via the link below. I recorded this via Hauptwerk on the Rotterdam (main organ) sample set by Sonus Paradisi.
Score: https://www.sheetmusicplus.com/en/product/prelude-on-st-denio-immortal-invisible-god-only-wise-organ-work-by-phil-lehenbauer-23548566.html?aff_id=478282