Two WordPresses and One Database

Hello good people,

Can I wire up a WordPress to an existing database on a completely different WordPress?

And…

Can I use different themes, plugins and pages on this second WordPress?

Why?

I want to keep the existing logins, posts, media, etc from WordPress #1 and test the themes, plugins and pages on WordPress #2 without damaging the WordPress # 1 database.

WordPress #1 is the current live site.

WordPress #2 is the new version of the site in development.

I know there are several ways of doing this, but this is the approach I prefer to go with–if it will work.

Thank you in advance,

Warmest,

Chris