"To Gild Refined Gold," or What Mozart Didn't Want Us to Embellish

The question of adding embellishments in music performance is generally regarded from a primarily practical perspective. In this article I make a case for embellishments as an object of music-theoretical inquiry in their own right. While exploring this question mainly in conjunction with Mozart's music for solo piano, I address the more fundamental question of what makes a given moment in the music suitable for added ornamentation. Tolerance to embellishment is defined as a quality of the melodic surface tantamount to the flexibility and exchangeability of melodic formulations with variants. Thus defined, only some of the embellishments notated by composers are indicative of a flexible melodic surface (optional embellishments), whereas others are shown to be irreducible owing to their participation in substantive thematic processes (obligatory embellishments). My investigation focuses on embellishments introduced in sonata-form recapitulations and other types of recapitulatory restatements (e. g., the return of the refrain in the rondo form). A movement's form and tempo are shown to affect its amenability to added ornamentation. At a local level, I draw on aspects of music perception and musical memory to account for a correlation between a passage's temporal position in the movement and its suitability for added embellishments. I conclude by pointing to a Mozart-specific category of unembellishable motives, demonstrably intended by the composer to be performed with no decoration. Engaging in a dialogue with Robert Levin's recorded embellished version of the slow movement of Mozart's Piano Concerto in A major, K. 488, this primarily theoretical discussion also leads to some tentative practical implications for performance.