This seems to be the closest I can find.

www.musicals101.com/
A must for musical fans this site is a huge cyber encyclopaedia covering everything to do with musicals on stage, on TV and in film. Aspiring Lloyd Webbers should read the section on putting on a Broadway show. There's a comprehensive history of the musical starting at the earliest stage musicals of the 16th century and going through to Hollywood's glamorous 20th century offerings. The site is the work of one man, musical mad John Kenrick who claims to have seen over 300 Broadway productions.
VERDICT: This exhaustive site is a comprehensive guide to the history of musicals on stage, on TV and in movies.

For opera, operabase.com/en/

The focus of the site is a huge 55,000 strong database of opera performances around the world, which you can search by singer, role, conductor or producer. Particularly useful is the news, reviews and previews section where you can find out what's coming up and where, and what's been and gone and whether it's worth going to see when it comes around again.
VERDICT: A rich resource for those of an operatic bent.