Who wrote the song which was sampled in Letting Go? 
Letting Go (Dutty Love):  As of December 2014, the song has sold 1.1 million copies in the United States. Te Amo (Rihanna song):  The electro-Latin song was written by Mikkel S. Eriksen, Tor Erik Hermansen, James Fauntleroy II and Rihanna, with production helmed by Eriksen and Hermansen under their production name, Stargate.
Mikkel S. Eriksen