Hummel's Concerto for Trumpet (Concerto a Tromba principale) is overtly operatic and is stylistically reminiscent of Mozart's Don Giovanni. Using the methodology of Leonard Ratner and Wye J. Allanbrook, it is possible to explore gesture and rhetoric in Hummel's Concerto for Trumpet and Mozart's Don Giovanni, and achieve a deeper understanding of the stylistic similarities shared between the two works. In the third movement, dance is the most significant link to Don Giovanni. In the second movement, Hummel alternates between the emotions of Donna Anna and Don Ottavio as they appear in act 1, scene 13. The first movement makes extensive use of contrasting topics identified with buffa and seria characters to advance the musical narrative. Comparing Hummel's concerto and Mozart's opera is a hermeneutical approach that illuminates several performance practice implications. Knowing the expressive similarities and rhetorical strategies common to both works clarifies several issues, such as tempo, ornamentation, and above all, expression. Though Mozart's Don Giovanni and Hummel's Concerto for Trumpet are unequal in significance, it would be valuable to any interpretation of Hummel's concerto if the performer and audience acknowledge that the work is rhetorically and stylistically similar to Mozart's Don Giovanni.