Alec Rupen Costandinos, (born Alexandre Kouyoumdjian in 1944 in Cairo, Egypt) is a French composer, music producer, songwriter and singer of the 1970s, famous for his contributions to the disco music. His father was Armenian and his mother was Greek. Costandinos dominated the disco and Euro-disco genres in the late 1970s. He began his career as a publisher and producer for various artists, including French pop star Claude Francois and chanteuse Dalida. After co-writing Cerrone's "Love in C Minor" (1976), Costandinos was signed to Barclay Records. He released his first album, Love & Kisses, in 1977, which featured the hit track "I Found Love (Now That I Found You)". Costandinos went on to release a number of wildly successful records under the prominent American disco label, Casablanca. His album, Romeo & Juliet has been credited for bringing the concept album to dance music. He also wrote "Thank God It's Friday," the theme track to the disco film by the same name.
Costandinos was intimately involved as a writer in the development of many productions of Demis Roussos. He also contributed to the debut album of Crystal Grass, which featured the club hit "Crystal World", released on the Philips label in France. He has also written under the pseudonym R. Rupen. He often worked with a collective of backing singers, The Birds of Paris, some of whom later became famous in their own right. According to what he declared in one of his rare interview on 11 December 2011 at Open House Radio (Miami) his disco works were basically influenced by Philly Sound, Classical and Melodic Italian Music.