Alex Alstone, born Siegfried Alexander Stein on December 30, 1903, in Hamburg, Germany, was a Jewish pianist, songwriter, arranger, and conductor who made significant contributions to music both in Europe and the United States. He emigrated to the USA on November 9, 1923, where he initially resided in Jacksonville, Florida, and declared his intention to become an American citizen. During World War II, Alstone served in the French Foreign Legion but was barred due to his German origin.

Alstone is best known for his composition "Symphony," which became a worldwide success after being translated and arranged globally. The song was originally known as "C'est Fini" in France and gained popularity after World War II. In the United States, it was recorded by artists such as Freddy Martin and became a hit on multiple Billboard charts in 1946.

Throughout his career, Alstone collaborated with notable artists including Tino Rossi, Maurice Chevalier, Tommy Dorsey, Joe Reisman, Charles Aznavour, Dean Martin, and Perry Como. He was also known under the pseudonym "Gaston Lecoque."

In the 1950s, Alstone led his own orchestra in New York and became a member of the Societe des Auteurs, Compositeurs et Editeurs de Musique (SACEM) in Paris in 1955. He eventually returned to Paris in 1958 and continued his work as a composer until 1979. Alex Alstone passed away on July 3, 1982.