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 Angel López, Pedro Quiles, and brothers Javier Montes and George Montes. In 1998, the group released two songs written by Alfanno, No Hay Razon and Nada. The songs were minor hits on the Billboard Latin Tracks chart