If a surprise guest is going to crash your YouTube video, you'd be hard-pressed to find someone better than former President Barack Obama.

Fred and Tim Williams, the YouTube sensation known as TwinsthenewTrend, who react to classic music, got just that treat. The 22-year-olds were reacting and discussing the Bob Dylan track "The Times They Are A-Changin" — which Obama included on his recent playlist tied to his book release — when Obama himself showed up.

"Hey people, what's going on?" Obama said. "I hear you guys were asking questions. I decided I'm just gonna go ahead and come here live."

The twins responded in shock, of course, before eagerly talking with Obama about music.

If you know the Williams twins, it's most likely from their very viral video reacting to Phil Collins' "In the Air Tonight" — their pure, joyous reaction to the drum solo was glorious. Obama talked with them about the value of exposing themselves to older music that's new to them.

"One of the most important things we can do as people — but especially young people — is opening our minds to how other people feel, what their traditions are, trying to make common cause with folks even if they don't look like us or didn't come from the same neighborhood," Obama said to the twins.

The former president told the YouTube stars that he included the Dylan song because he's a longtime fan and wanted to include the message of the track.

"We asked the president what the song meant to him, and he said the old ways are not going to work. Times are changing,” Tim Williams told People. "He gave us hope that there are still good people in power that want to see a change for the better."