Son by Four is a Latin music group from Puerto Rico, well known for their English U.S. pop hit "The Purest of Pain (A Puro Dolor)".

The songs were minor hits on the Billboard Latin Tracks chart, helping Son by Four sign a recording contract with Sony Music.

"A Puro Dolor" ranks at number one in Billboard's Decade-End Latin Songs of 2000s chart.

[1] The English version of the song ("Purest of Pain") placed at number 26 on Billboard's pop music charts.

[2] "A Puro Dolor" helped Son by Four earn gold sales status, and it received four prizes at Billboard Music Awards (December 2000) and seven prizes the Billboard Latin Music Awards (April 2001), including Hot Latin Track Artist of the Year.