Usage and Grammar

Q. CMOS 5.250 says “media” is the plural of “medium” in re mass communications. Please advise if these sample adjectival constructions are wrong: public media archives, public media community, the new media landscape, public media practices, media companies, media platforms. Often a substitute noun would be singular: senior community, university practices, computer platforms.

A. Yes, but such constructions can also be plural: seniors community, books archive, problems database, toys catalog. And given that “media” is often construed as a singular noun, your constructions can be considered correct.