For today's Geo Quiz -- a Slavonic dance. Czech composer Antonin Dvorak composed his Slavonic Dances back in 1878.

Dvorak probably didn't imagine his "dances" would be so popular a century later, performed by orchestras world-wide.

Nor could he know that his work would be part of a "digital concert hall."

That's a new concept being rolled out by a world-famous symphonic orchestra.

And for our quiz today, we're looking for the European city that's home to this orchestra.

It's set to play the Slavonic Dance in G minor -- on January 6th --- in its new digital concert hall.

For now -- all you have to do is name the city -- which is located where the Rivers Spree and Havel join up...