Complex sentence: Septiembre Musical is a yearly international arts festival that takes place in the province of Tucumán, Argentina, from 1960 to present, organized by the provincial government and considered by its permanence and quality one of the most important meetings of its kind inside the country.
Split into simpler sentences: Septiembre Musical is an annual international arts festival that takes place in the province of Tucumán, Argentina. From 1960 to present, it has been organized by the provincial government and considered (because of its permanence and quality) one of the most important meetings of its kind inside the country.