London-born Harold Lester studied music at Trinity College of Music, specializing in all aspects of keyboard work. He has been principal pianist with the London Symphony Orchestra, the Royal Philharmonic Orchestra, the New Philharmonia Orchestra, the London Philharmonic Orchestra, and the London Sinfonietta, frequently as a soloist. He toured the world as an accompanist with the late Cathy Berberian for some ten years, performing the world premiere of Berio's Recital 1 and playing in major festivals. He has worked alongside contemporary composers including Berio, Stockhausen, Ligeti, and Messiaen. He is a specialist in Baroque music and has toured internationally as a solo harpsichordist. As a continuo player, he has played and recorded with leading chamber orchestras and many Baroque chamber groups. He is professor of harpsichord and Baroque music at Kingston University, and has worked extensively in the world of opera as a répétiteur.