Information - Read The Study Pages contain special players for all the songs of the editions, with accompaniment arrangements and that allow you to play the scores at different speeds, change the volume of the melody or other instruments and also enable or disable the hearing of any one and also inclusion of metronome. This way you have both an option for adjustable playback as well as the demonstration of the melody synchronized with the score. They now include Demonstrative Videos of the songs and Playbacks recorded with old and traditional instruments. The subscription is made in a single purchase and allows access for at least 2 years.