The article is an outline of the study on negative valorization of magical musical instruments appearing in some folk tales. The starting point for the author's discussion became the tales with the motif of a magical fiddle. In the work by Julian Krzyzanowski (classification of motifs) these tales were classified as the type T 592. The tales tell about situations in which magical objects play an important role. Musical instruments are among these objects, the musical instruments which provoke expressive, dynamic behaviour of the listeners. Analogies can be found between the scenes in the narratives and those depicted on medieval illustrations showing diabolic interference into human life. They can also be compared with the texts describing witches' covens. In both representations motifs of music and instruments appear, as well as dance- acts disapproved by Church. Due to such context musical instruments acquire negative attributes and then become magical objects. This is reflected in magical tales with the motif of magical fiddle. The above mentioned relationship shouldn't be considered as the only origin of attributing magical significance to music and instruments. References to magical power of sound and instruments can be found in the texts coming from other parts of the world, which may prove the common origin of the cultural concepts of music and musical instruments. The author suggests another interpretation of the discussed tales as well. Interpretation of the contexts and the relationship between the musicians and the listeners. The spell results from the ambivalent attitude of the listeners to the forms of sonic and verbal expression accompanying the music itself, as well as appearing of the musical instruments in the context of the characters with negative valorization. Their magic is concealed in the expressiveness of the listeners, in their dynamic responses which are the explosion of their feelings. It is rather the instrument that has been, as it were, enchanted by the listeners. The relationship of the instrument, its owner and the listeners is that of metonymy.