An Equal Music is set mainly in London and gets its title from a sermon by John Donne. Its first-person narrator, Michael Holme, is in his mid-thirties and plays second violin for the Maggiore Quartet. Michael grew up in northern England and studied at the Royal Northern College of Music in Manchester. Michael’s former teacher at the Musikhochschule in Vienna, Carl Käll, has been long retired in Sweden, but he remains a powerful presence in Michael’s imagination because he had foretold Michael’s collapse at a concert: “It was because he had said I would fail, and I could see him in the audience and knew he had willed me to.” A second haunting figure in Michael’s life is Julia McNicholl, a fellow student whom he had loved and abandoned after his Vienna failure. All of this happened ten years ago. Julia is now a wife and mother, and Michael bitterly regrets his decisions.
Michael’s comusicians in the quartet are Helen, the viola player; Helen’s older brother, Piers, first violinist; and Billy, cellist and composer. Leaving Wigmore Hall one night after a program of Joseph Haydn, Wolfgang Amadeus Mozart, and Ludwig von Beethoven, Michael runs into Julia, and their old romance is soon rekindled as an adulterous affair. The Maggiore Quartet’s success wins it a contract to record Johann Sebastian Bach’s Art of Fugue, as well as an important concert in Vienna. Piers, however, not knowing of Julia’s deafness, invites her to join them in playing Franz Schubert’s Trout Quintet. Ambiguities in their rehearsal force Michael to reveal Julia’s deafness, a challenge that is surmounted by providing Julia a strong bass sound to follow, and the program at the Musikverein goes off well, despite Michael’s debilitating nervousness.
Julia follows the quartet to Venice, and all is well until Michael reads a loving fax that Julia has sent her husband, and his cruel comments wound Julia beyond reconciliation. Back in London, Julia’s husband, James, a former Boston banker, invites Michael to a party at which James’s coolness tells Michael that he knows of the affair. Michael soon quits the quartet when he discovers that Julia has scheduled a performance of the Art of Fugue, and when he goes to hear her play at Wigmore Hall he leaves at the intermission and walks off in the rain.