The plot concerns Michael, a professional violinist, who never forgot his love for Julia, a pianist he met as a student in Vienna. They meet again after a decade, and conduct a secret affair, though she is married and has one child. Their musical careers are affected by this affair and the knowledge that Julia is going deaf.

A recurring element throughout the plot is the pair's performance of Beethoven's Piano Trio Opus 1 No.3, which they first perform in their college days.

Seth together with Philippe Honoré marketed a double CD of the music mentioned in An Equal Music, performed by Honoré.^[1]

The book was especially well received by musical fans, who noted the accuracy of Seth's descriptions of music.^{[citation needed]}

Paolo Isotta, one of Italy's most significant music critics, wrote in the influential newspaper Il Corriere della Sera of the Italian translation that no European writer had ever shown such a knowledge of European classical music, nor had any European novel before managed to convey the psychology, the technical abilities, even the human potentialities of those who practise music for a living.^[2]

Several musical works figure prominently in An Equal Music. Among these are the Trout Quintet by Franz Schubert, the String Quintet in C minor by Ludwig van Beethoven, and The Lark Ascending by Ralph Vaughan Williams.