I would like to add that I have all these 3 sets of Bach Organ Works, performed by Lionel Rogg for the Oryx, EMI & Harmonia Mundi record labels.
As a student, I idealized his mid-1960's 'Oryx Recordings'. But yesterday, I serviced my old Rotel turntable and replayed some of the LPs from the Oryx series; comparing them against my EMI remastered, mid-1970's CD versions,(also played by Rogg on 'modern' organs) - and then my 'Harmonia Mundi' CD set on a Silbermann Organ.
Sorry, but I don't know how anyone today can be content, after listening to the original technical sound quality emanating from the LP's! Apart from the 'snap, crackle & pop', the stereo sound is narrow and compressed. There is no really wide, dynamic, aural spectrum either. Also, one notices the really low-signal to high-noise ratio. Thank God for the wonders of digital remastering, otherwise you'd fail to appreciate much of Rogg's interpretive detailing.
I had deluded myself, entertaining once-rosy memories, gained in the early 1970's. No way would I praise Rogg's 1960's recordings as being 'more authentic.' Let's say the Oryx recordings were groundbreaking for their time, but now there are 2 other series, newly remastered onto the CD format, which better proclaim and capture Rogg's interpretive skills.
Bach organ buffs may also care to purchase the excellent 15-CD 'Berlin Classics' series, (re-released approx 2008). All these very early (1960's-1972) former VEB/edel/East German State recordings use several wonderful, different sized, GDR located, Silbermann organs. They also benefit from a 'sonic-soundmapping'(?) i.e. ADD reprocessing, which translates as "VERY presentable; clean, wide-ranging sound." The 10 different East German organ virtuosi (emanating from the former DDR's musical schools in Dresden, Weimar & Leipzig), furnish one's ear with very thrilling, clearly articulated performances.