Son By Four is a salsa music group from Puerto Rico, well known for their English U.S. pop hit "Purest of Pain (A Puro Dolor)". The group is signed to Sony Music Entertainment.Son By Four was created by Panamanian producer/songwriter Omar Alfanno and integrated by Ángel López, Pedro Quiles, and brothers Javier Montes and George Montes.Footnotes^ "Top Latin Songs of 2000s". Billboard. Retrieved 2012-08-01. ^ "Son by Four's 'Pain' Aimed at Crossing Over". Billboard. Retrieved 2012-08-01. ^ "Son by Four in tune with Billboard Latin". Variety. Retrieved 2008-07-02. ^ "Son by Four regresa con música cristiana". People en Español. Retrieved 2012-08-01.