Javier Ibarra Ramos, better known by his stage name Kase.O, is a Spanish rapper, songwriter, and producer who is a part of the Violadores del Verso rap collective with DJ R from Rumba, SHO-HAI, and Lrico. He is typically regarded by the public and the media as one of the most well-known rappers who speak Spanish. He has been active since 1993 and is regarded as the standard and king of Spanish rap. With Violadores del Verso from 1998 to 2006, Kase.O released up to seven studio albums during the course of his career. Then, in 2011, he released "Kase.O Jazz Magnetism"solo, a hip-hop and jazz album, remastering several classics from Zaragoza and writing new songs with the band Jazz Magnetism.