Complex sentence: Jose Reyes and Manitas de Plata and become the first gypsy artists to perform on such prestigious stages, they also give a concert at the United Nations, after which it will be decided to establish a permanent representation of nomadic peoples in the institution.
Split into simpler sentences: Jose Reyes and Manitas de Plata became the first gypsy artists to perform on such prestigious stages. They also gave a concert at the United Nations, after which it would be decided to establish a permanent representation of nomadic peoples in the institution.