Degradation marks of phonograph cylinders from Tesař’s opera collection

Phonograph cylinders are the oldest commercially available recording media and are an valuable part of cultural institutions’ collections. Even though they are an essential part of sound history, they have long been overlooked as a relatively chemically stable media. The only degradation mentioned in the literature was a whitish cover, traditionally appointed to microbiological growth. In our study, we focused on unravelling the issue of these degradation products. A selected collection from the National Museum – Czech Museum of Music was subjected to microbiological and analytical examination via digital microscopy, FTIR spectroscopy, colourimetry and SEM-EDS analysis. From the results, some of the degradation pathways were proposed. The results also help us to focus future research and suppress the degradation so that the cylinders stay longer in conditions fit for digitisation and overall archivation.