Lester Sill (1924–2008) was an influential American music producer and entrepreneur, primarily known for his work in the pop and rock genres during the 1950s and 1960s. He played a pivotal role in the development of the Los Angeles music scene and was instrumental in shaping the "Brill Building" sound, characterized by its polished production and catchy melodies. Sill co-founded several record labels, including Era Records and later, the successful partnership with Phil Spector at Philles Records. Notable works include producing hits for artists such as The Righteous Brothers and The Crystals. His collaboration with Spector helped in crafting iconic songs like “You’ve Lost That Lovin’ Feelin’” and “He’s a Rebel,” both of which became classics. Lester Sill's impact on music is significant; he not only helped launch the careers of various artists but also influenced the production techniques that would dominate the industry. His knack for blending innovative sounds with commercial appeal made him a key figure in the transition of popular music during a transformative era, leaving a lasting legacy in the realm of rock and pop music.