The first legal issue is breach of contract. Against the terms of the agreement which was that Martina would not sing for another agency until five years elapsed, she did sing for a Russian agency. To get out this,Martina needs to rely on the fact that they made a verbal agreement with the owner of S & E ,and she was on the right because she sang an aria.
The other issue is obtaining commission from another agency which under the agreement was not warranted and as such she owes S & E a commision. However, Martina could challenge this by making it clear that she obtained commission for a different kind of music,different from what she signed for with S & E.
What are the legal principles related to issues?