Ellie Greenwich was an influential American pop music singer, songwriter, and producer active predominantly in the 1960s. She is best known for co-writing chart-topping hits such as "Be My Baby," "Da Doo Ron Ron," and "River Deep - Mountain High," which helped define the girl group sound of the era. Greenwich's work, characterized by its catchy melodies and emotionally resonant lyrics, significantly contributed to the development of the Brill Building pop genre. Her collaborations with Phil Spector, particularly in the realm of the Wall of Sound production technique, have left an indelible impact on pop music.