Why do records play at 33 1/3 rpm?
QuestionHow were record speeds worked out? Why 33 1/3, 45 and 78 revolutions per minute?
Answer** Definitive **
Name: Brian, Thurrock
Qualification: Record collector
Answer: The change when 78s became 33s came when they changed the material they were made from. The high revolution speed would have been detrimental to the vinyl. 33 was chosen as due to the area on the disk and the length of music it can hold. It’s the most amount of music you could fit on without reducing the quality of the reproduction.