Complex sentence: She also plays the flugelhorn brilliantly, and is allowed to play with the local brass band after playing Concierto de Aranjuez with them, the band is made up of miners from whom she must conceal her purpose.
Split into simpler sentences: She also plays the flugelhorn brilliantly, and is allowed to play with the local brass band after playing Concierto de Aranjuez with them. The band is made up of miners from whom she must conceal her purpose.