So begins “La Bola Negra,” an extravagantly overwrought epic from the Spanish directors and screenwriters Javier Ambrossi and Javier Calvo, with the first of a few clever, if tortured, winks. The trumpeter (played by the singer Guitarricadelafuente, in his screen-acting début) is himself named Sebastián, though when he beholds that fallen statue he sees only a means of escape, not a famously martyred namesake or a marble-muscled icon of homoerotic desire.