cadences · peterson-omt-intro-harmony

One way to create a sense of closure at the end of a phrase is through cadences —melodic and harmonic patterns that create goals, kind of like punctuation marks in literary sentences. They're important not only because they can help you determine phrase endings, but also because they help establish a key. ... Authentic cadences involve the progression V–I. They are perfect when both harmonies are in root position and do is in the soprano over tonic. If either of these conditions is not met, the authentic cadence is imperfect. ... A half cadence (HC) occurs when a phrase ends on V ... PACs are the strongest kind of cadence available to a composer because of the sense of finality they can create, and HCs are the weakest kind of cadence because of their unfinished sound.