The paper deals with the possible similarities in workings with text of legal and musical interpreter. Whether the text is legal or musical, it needs to be interpreted and perfomed to the audience. Which interpretation can still be considered as “based on text”, and which as “buit on text”? It is possible co compare overinterpretation, or improvisation to the inlimited distretionary, or are these seemingly free from rules ways of interpretation also subjects to some methodology? The article shows what can lure the interpreters to cross the line, what this crossing really means and in what occasions (if there are any) is it desirable.