There's a book: 7 Languages in 7 Weeks that tries to pick a language from different "domains" (functional, imperative, prototype...) Might be what you're looki

There's a book: 7 Languages in 7 Weeks that tries to pick a language from different "domains" (functional, imperative, prototype...) Might be what you're looking for, a quick way to asses the landscape. As for mastery: yes, you need to be able to master at least one language, and plan to always master the language you are going to use the most.