Playback speeds were not standardized until the late 1920s or early 1930s, and most discs were originally cut at speeds ranging from 76-80rpm (and some well beyond). were all digitized at a playback speed of 78rpm. Preservationists and collectors debate extensively about the “correct” speed at which discs ought to be played back, and whether one ought to pitch discs individually. However, performance, recording and manufacturing practices varied so widely that even if a base speed could generally be agreed upon, there will always be exceptions. (For more on this, please check out George Blood’s forthcoming paper Stylus Size And Speed Selection In Pre-1923 Acoustic Recordings in Sustainable audiovisual collections through collaboration: Proceedings of the 2016 Joint Technical Symposium. Bloomington, IN: Indiana University Press.)
Every step of making a recording involves so many aesthetic decisions – choices of instrumentation, methods of sound amplification, microphone placement, the materials used in the disc itself, deliberate buy sales lead pitching of the instruments and slowing or speeding of the recording – that playback speed simply become one of many aesthetic choices in the chain. As preservationists, we are preserving the disc as an historic record, not attempting to restore or recreate a performance. (Furthermore, speed correction is possible in the digital realm, should anyone want to modify these digital files for their own personal enjoyment).
How do they sound? Each 78rpm disc has an inherent noise fingerprint based on the frequency and dynamic range the format can replicate (limited, compared to contemporary digital playback formats) and the addition of surface noise from dust, dirt and stylus wear in the grooves. As expected, the sound quality in this collection varies. Some of these discs were professionally recorded, minimally played, stored well, and play back with a tolerable, even ignorable level of surface noise relative to the musical content. Others were recorded under less professional circumstances, and/or were much loved, frequently played, stored without sleeves in basements and attics, and therefore suffer from significant surface noise that can interfere with enjoyment (and study) of the music.