The invention relates to a musical instrument with which a sound is produced in the same manner as when playing the guiro (Latin American percussion instrument: longish gourd having a regularly notched surface) by scratching with the finger nail or by playing with a playing aid. In contrast to the guiro or also to the percussion instrument called a washboard, sound rows can be made of individual modules or sections. Playing in a constant tempo enables the production of analogous rhythms due to the constructed interval ratios and scales can be produced by combining different frequencies. Particular embodiments of the instrument and of the playing aid made of different materials produce many nuances in sound that challenge the creativity and the curiosity of the player even more. Possible materials include wood, paperboard, plastic, rubber, metal, ceramics and stone.