Graham Stack  has written and produced hit records for many artists including a singer who relinquished her American what?
Tina Turner Tina Turner (born Anna Mae Bullock; November 26, 1939), is an American-born Swiss recording singer, songwriter, dancer, actress, and author. Born and raised in the Southeastern United States, Turner relinquished her American citizenship after obtaining Swiss citizenship in 2013.
Whitney Houston Whitney Elizabeth Houston (August 9, 1963 – February 11, 2012) was an American singer, actress, producer, and model. In 2009, "Guinness World Records" cited her as the most awarded female act of all-time. Houston is one of the best-selling music artists of all-time, with 200 million records sold worldwide. She released seven studio albums and two soundtrack albums, all of which have diamond, multi-platinum, platinum, or gold certification. Houston's crossover appeal on the popular music charts, as well as her prominence on MTV, starting with her video for "How Will I Know", influenced several African American women artists who follow in her footsteps.