"Gwendolyne" by Julio Iglesias is performed in the original key of E minor. The song was written by Jean Kluger and Daniel Vangarde. Released in 1970, "Gwendolyne" is one of Julio Iglesias's early hits and helped propel him to international fame. Julio Iglesias, a Spanish singer and songwriter, became one of the best-selling Latin music artists of all time. "Gwendolyne" is a romantic ballad with a captivating melody and heartfelt lyrics, showcasing Iglesias's smooth vocal delivery and emotional depth. The song tells the story of a man lamenting lost love and longing for the return of his beloved Gwendolyne. With its poignant lyrics and melodic charm, "Gwendolyne" remains a classic in Julio Iglesias's repertoire.