Guillermo Cases was a Spanish composer and conductor active during the early to mid-20th century. He is known for his work in Spanish theater and film, contributing to various productions as a musical director. One of his notable collaborations was with singer Imperio Argentina on the song "Caminito del Rio." Additionally, Cases conducted the Orquesta Estable del Teatro Colón in performances of Spanish classical music. His contributions to Spanish music have been recognized for their influence on the country's cultural heritage.