Of the operas Eugene Onegin or The Devil and Kate, Eugene Onegin had more contributions to its making from friends of the composer of the opera.
Eugene Onegin (Russian:   , "Yevgny Ongin"), Op. 
 Tchaikovsky's friend Konstantin Shilovsky contributed M. Triquet's verses in Act 2, Scene 1, while Tchaikovsky himself arranged the text for Lensky's arioso in Act 1, Scene 1, and almost all of Prince Gremin's aria in Act 3, Scene 1. 
The Devil and Kate, Op. 
 112, B.201, ("ert a Ka" in Czech) is an opera in three acts by Antonn Dvok to a Czech libretto by Adolf Wenig. 
