Certain pieces of music in the repertoire of any instrument stand above the rest. Young players study them as a rite of passage, professionals perform them as standard repertoire, and audition committees request them to assess the candidate's musicality. For the trombone, two such pieces are the Romance attributed to Carl Maria von Weber and Ferdinand David's Concertino. Despite the importance of these pieces in all phases of a professional trombonist's career, less scholarly attention has been paid to them than to the repertoires of other instruments. The purpose of this document is to provide an interpretation of these works to be used as a guide to successful performance. This interpretation will be informed by formal and historical overviews. The creation of this path to competency requires a thorough historical investigation. This look at history is also interesting in its own right, as both pieces feature interesting backgrounds. The Romance was likely not written by Weber or intended for the trombone, yet it is known as the Weber Romance for trombone. Felix Mendelssohn originally intended to write the Concertino, but passed that responsibility to his concertmaster, Ferdinand David. If Mendelssohn had set a precedent by writing a trombone solo, perhaps the other great composers whom Mendelssohn influenced would have followed suit. These facts can at the very least provide the aspiring trombone soloist with a sense of context for preparation of these works. The core of this document is a phrase-by-phrase interpretation of each work coupled with the historical background. The process of combining this historical background with information about the structure of the piece, period performance practice, and the mechanical problems specific to the trombone forms the base from which the successful performing musician works. This "performer's guide" is not meant to be a method book or a practice guide but rather an informed application of music theory and historical knowledge to the composer's musical content in these pieces.