Middleton was born on January 10, 1981, in Cirencester, Gloucestershire, England. At the University of Birmingham, he took lessons on the piano with Jeffrey Harris; he also studied the violin, flute, and organ, before graduating with a Master's degree in philosophy. Before graduation, he won conducting and concerto prizes, which helped him earn an EMI scholarship to study piano at the Royal Academy of Music, where he was taught by Malcolm Martineau and Michael Dussek; it was Martineau who introduced Middleton to the song repertoire that would become the focus of his performing career. While attending the Royal Academy, he won several awards for accompaniment, including from the Wigmore Hall International Song Competition, and the Kathleen Ferrier, Richard Tauber, and Geoffrey Parsons Awards.
Upon completion of his studies at the Royal Academy, he immediately began accompanying leading vocalists, including Sir Thomas Allen, Dame Felicity Lott, and Dame Sarah Connolly; he has toured and recorded with all three. Among the star-studded list of vocalists he's accompanied are Mary Bevan, Ian Bostridge, John Mark Ainsley, Roderick Williams, and many others. Middleton made his BBC Proms debut in 2016, performing with Iestyn Davies and Carolyn Sampson. In 2017, Middleton became the first accompanist to win the Young Artist Award from the Royal Philharmonic Society. He returned to the Proms in 2018, joining Connolly in premiering recently discovered works by Britten.
Middleton has recorded for the BIS, Champs Hill, Chandos, and Signum Classics labels, among others. His recordings have earned him an Edison Award (with Sampson for A Verlaine Songbook) and several nominations for awards from BBC Music Magazine and Grammophone. He was heard on several releases in 2020, including Lines Written During a Sleepless Night with Louise Alder, on Chandos, The Contrast: English Poetry in Song with Sampson, on BIS, and Schumann: Stille Liebe with Samuel Hasselhorn, on Harmonia Mundi.
After a Junior Fellowship at the Royal College of Music, Middleton returned to the Royal Academy as a professor of piano; he was later named a Fellow. He is a musician in residence at Cambridge's Pembroke College and is the director of Leeds Lieder. ~ Keith Finke, Rovi