Once the initial test has been carried out, the teacher will be able to decide which exercises and activities are most suitable for his/her group. In this dossier some exercises are offered at an elementary level and others with a certain degree of complexity, so that their didactic potential is useful for everybody. All the teaching and learning activities have been designed for the computer and some for the synthesizer, whilst bearing in mind the difficulty that writing music entails for the pupils - this will be an element to be dealt with and developed throughout the dossier, in such a way that pupils will have to practice writing music on music paper. The teacher will decide, according to their criteria, which exercises are most appropriate for writing on music paper. Music writing in a notebook or music paper will also allow us to deal with diversity in the class, since not all the pupils experience the same difficulties with the precision of musical language. The fact that the computer simplifies tasks of edition and execution of a musical piece has great advantages, such as asking the pupils to do more complex exercises than those we could ask them to do otherwise. When initiating the activities it is recommendable to find a system which enables the saving of the work being done by the pupils. It is advisable that each group of pupils (two or three) working on a computer save their work on disk. The pupils should learn to save the pieces they write. Equally, for the group or for pupils' and teachers' knowledge of I.T., directories and subdirectories can be created to organise the work.