At Oxford University he studied research methods into early music performing practices, specializing in the 16th and 17th centuries. He became a musical assistant to composer Sir Michael Tippett, himself one of the earliest British music figures of the 20th century to develop a strong interest in Renaissance English music. Tippett was associated with the Bath Festivals, and suggested that Parrott form a choir for Renaissance music performance in the 1973 festival.
Following Tippett's suggestion, Parrott organized the Taverner Choir, named after John Taverner (ca. 1490-1545), a leading English composer of that era. The Choir was a success, remaining in existence continually since then. Subsequently, Parrott organized the Taverner Players and the Taverner Consort with the same musical emphasis. The Players or Consort often appear with the Choir.
Parrott and the Taverner groups have built one of the leading reputations in Baroque and pre-Baroque music. They appeared at the 1977 Promenade Concerts in London with Monteverdi's Vespers, and were the first to give a period instruments performance in London of Bach's Mass in B Minor.
Parrott's conducting career includes substantial work researching, writing, and lecturing on early music. It also includes a substantial amount of performing later repertory, and has expanded to a sizable involvement in opera.
He has appeared with the Orchestra of the Age of Enlightenment (a period-instruments group devoted to the classical and early romantic eras), and has a close relationship with the Slovak Philharmonic and the Residentie Orchestra of The Hague. In 1989 he became Artistic Director of the Kent Opera, and has conducted at La Scala, the Royal Swedish Opera at Drottningholm, and the Royal Opera House at Covent Garden, London. He is an active conductor of modern music, including works of Tippett, Taverner, Nono, Varese, Britten, and Stravinsky, and premiered Judith Weir's A Night at the Chinese Opera. Before becoming an exclusive Sony Classics artist, Parrott recorded on the L'Oiseau-Lyre and Hyperion labels and on the EMI Reflexe label. Most of the Reflexe recordings are being transferred to the EMI firm's Virgin Veritas imprint. ~ Joseph Stevenson, Rovi