The unpublished concert aria, "Ch'io t'abbandono," by Felix Mendelssohn Bartholdy (1825), is representative of the adolescent composer's developing musical aesthetic. In this study, Mendelssohn's education, work ethic, and perfectionism are revealed, paradoxically, as both the catalysts for the piece's composition and also the reasons it was not published during Mendelssohn's lifetime. An exploration of the text, form, thematic usage, and performance demands of the aria yields specific examples of his uniquely balanced romantic-classicist style. A consideration of possible original performers of the piece, Franz Hauser and Eduard Devrient, leads to further discussion about the nature of the work as both a reflection of Mendelssohn's romantic self-expression and his appreciation for the Baroque melismatic style. The significance of the aria, both stylistic and biographical, is further delineated by a presentation of possible motivations for its composition. The musical setting of the text, as well as the text itself, indicates both Mendelssohn's awareness of himself as a maturing adolescent composer and his desire to be a composer of operatic works, a desire that was never fully realized.