The Traca Valenciana is the most traditional firework of the city and nothing screams Valencia more like this firework string, loaded with firecrackers. If you pay attention at any given Mascletà you will hear first a Traca go off, often ignited by the Fallera Major of the organizing Casal, if it's a street Mascletà.
But you also can hear them during the main 2pm Mascletàs at the Plaza del Ayuntamiento during Fallas. In this video the Traca was set up for the newly wed couple leaving the Santa Catalina church. It was just fascinating to see how tourists would just basically step on top of the Traca only to find out after it went off that they stood on explosives, hehe.