Belén Aguilera

Midway through the 2010s, Belén Aguilera, who had trained himself to sing and play the piano, started posting cover songs online. She swiftly rose to fame as "The girl and the piano," and in 2016 she received an invitation to compete on La Voz, the Spanish version of The Voice. She qualified for the knockout phase and, as a result, was among the final 10 players on her coach Melendi's side. Building off of this, she and Raoul Vázquez applied to Operación Triunfo the next year, but she was rejected while he was approved. After all, she collaborated with Vázquez to record the song Tus monstruos, which garnered further recognition in 2018.