Oscar Nunez from The Office was interviewed recently for IGN TV and he mentions Angela a few times:
“IGN TV: Angela [Kinsey] told me that in Season 1, you guys would just begin doing little improvs in the accounting section in the background.
Nunez: Yeah, I’ve known Angela for years and years and we’ve done improv together, so we were dying to show them what we could do. So the first shows, we would call Greg aside and go “We’ve got a little bit we’ve worked on!” And he’d say, “Go ahead and do it,” and [director] Ken Kwapis was open to it too. And they’d look and go, “Yeah, that’s not bad!” They’d shoot it. They wouldn’t use it, but they’d at least be respectful enough to at least shoot it, and not in a condescending way, but kind of like “You guys are doing good. Keep it up. We’ll find a place for it eventually.” And that did pan out in the end. But we were always chomping at the bit to show them what we could do, because we knew we could do this, you know?”