Stylus Size and Speed Selection in Acoustic Era 78 rpm Discs - Finally an Answer

In the early 20th century sound recording was a brand new, rapidly evolving form of entertainment. As the new field of "recording engineer" evolved, the world evolved around them. There was no universal standard for pitch, no synchronous motors to stabilize speed, standards of measurement were still evolving as well. Documentation of practices and manufacture are few and incomplete (and...possibly incorrect!). We're left to reverse engineer recording practice from the artifacts - the 78 rpm discs themselves. This tutorial will demonstrate and explain the underlying issues, then present the results from analyzing 10,000 digitized acoustic era discs. Working under contract from the Library of Congress and New York University, thousands of sides were preserved, including pristine "the stuff of collectors' dreams" discs from the Eldridge Johnson Museum and the Thomas Edison National Historic Park; as well as an equal number of discs "much loved in the wild". Included in the findings are an analysis of the work of Marcos Sueros on double blind stylus selection tests presented at IASA 2015 in Paris. I also expect to have data from a brand new project with the Internet Archive to use the findings on large scale 78rpm digitization. This is a greatly expanded version of the paper given at JTS2016 in Singapore.