Final answer:
A cadenza is a solo passage often featured in a concerto movement, allowing the soloist to exhibit virtuosic skills before the final orchestral ritornello. It should not be confused with other musical terms such as cadence, crescendo, or concerto.
Step-by-step explanation:
The term "C" that is used for a musical passage added at the end of a movement to provide a fitting conclusion or climax is cadenza. A cadenza often appears in a concerto movement and is typically a solo passage that is improvised or written out by a soloist, allowing for a display of virtuosic skills. It traditionally occurs just before the final orchestral ritornello, where the thematic material of the movement is reprised by the orchestra to bring it to a close. However, it is important not to confuse cadenza with a cadence, which is a sequence of chords that brings a piece or a section of a piece to its end, or a crescendo, which is a gradual increase in volume, or a concerto, which is a musical composition featuring a soloist or group of soloists and an orchestra.