Taking into account the basic elements of music (melody, harmony and rhythm) a simple composition is carried out, in a major key and using only two chords (tonic and dominant seventh). The Musical Abacus is used for obtaining the notes involved in the melody and the chords. Nuño Fernández, L. (2018). Example on Composition with the Musical Abacus. http://hdl.handle.net/10251/104578