Final answer:
The entries of the oboe and viola during a coda in Mendelssohn's composition could be fugue-like, syncopated, virtuosic, or serene and legato, depending on the particular piece. However, the specific details cannot be provided without knowing the exact work referred to.
Step-by-step explanation:
The question pertains to the entry of the oboe and viola during the coda of Mendelssohn's composition. Without specifying which of Mendelssohn's works is being referenced, it is challenging to provide a precise answer. However, in the context of many classical compositions, both instruments often employ different types of musical entries within a coda. A fugue-like motif would involve a contrapuntal entry where each instrument repeats a theme introduced by the other. If they enter with a syncopated rhythm, this means the instruments would emphasize off-beats or unexpected parts of the measure. An entry with a rapid, virtuosic passage would showcase the technical proficiency of the players with fast notes and complex sequences. Lastly, a serene, legato melody would be smooth and flowing, connecting each note smoothly to the next without noticeable breaks. While the provided excerpt illustrates various musical expressions, it doesn't directly describe the entries of oboe and viola in a coda by Mendelssohn.