This page is to be expanded over time. Please revisit it as time passes as it will hopefully have deeper information and more Korean language text. (It’s probably going to be a 2016 project)
A very basic chronological outline is below of the pre-vinyl and vinyl era.
Comprehensive information about early records in Korea can be found here: http://sparchive.dgu.edu/v2/
Emil Berliner develops gramophone record technology then patents it in 1887.
First flat gramophone discs come onto the market. These are 7 inchers that compete with the existing cyclinder format.
Mass production of shellac records begings in Germany.
10 inch 78 rpm Standard Play Records consolidate their position as the dominant format, except in the case of classical and opera music which is released on 12 inch discs.
The first vinyl 10″ LP is released in the US by Columbia Records.
The first vinyl 7″ 45rpm single is released in the USA by RCA in 1949.
The first 45rpm records are released in the UK by EMI
The London label releases its first 7 inch single in the UK. This label goes on to licence recordings from US labels such as … wide groove 
Rock ‘N’ Roll emerges.
Vinyl records are first released in stereo. The 78 rpm Standard Play format is phased out, although the format is still used into the early 60s in India and the Philippines.
CDs begin to take over as the primary format music is released on. By 1992 most major labels have ceased pressing commercial vinyl, leaving the format to small independent labels and a niche market.