Trepak International AB was created in 1981.

Check out this link for the notes of Trepak on the violin: http://www.scoreexchange.com/parts/70352.html

There are no lyrics to the song Trepak because it is an instrumental piece. It is by Pyotr Ilyich Tchaikovsky from the famous ballet The Nutcracker.

There are a few different national dances of Russia. But the most famous one are Barynya and Trepak.

Yes

You can find them in Act 2 scene 8 - By Invitation Only

They dance to the Trepak music (the Russian dance) from Petipa's original