If you have to listen to in a concert hall or on TV - Concerto for piano, violin or cello with orchestranote at the end of the first part. Sounds Reprise. Hear the music that the composer has constructed the first part. Then blend, then oppose each other orchestra and solo instrument. This seems to be soon completed.
But the conductor suddenly lowers his wand. The orchestra falls silent, and begins virtuoso solo. This is sort of a fantasy on the theme of the concert. Solo instrument manifests in all its possibilities. And fast passages, and powerful chords, and melodic and energetic melodies alternate with one another. The final chord of the cadence is attached, at a signal from the conductor, the orchestra, and together all the musicians complete the part.
Once, in the eighteenth century, composers were not composed cadenzas. Each soloist improvised her during the performance. Beethoven was the first to write cadenzas for his concerts. After it began to do and other composers. And cadence acquired more organic in nature, it is better to merge with the form of the whole work.
The word "cadence" (from the Latin cadere happened Italian cadenza and French cadence, which means the end) there is another meaning: this is the final harmonic and melodic turn, the final small musical episode, giving it a finished look. In this sense, often used the word cadence, that is the French version of the term.