I-V-I

Hello everybody! This is Dr. Meier here with a video for you on chord progression 1-5-1. We are going to understand the structural and dynamic role of this progression by exploring basic cadences and the addition of the 7th to the 5 chord. 1-5-1 is the basic progression of 18th and 19th century tonal music. I cannot overstate the importance of this basic progression. It acts as the bookends of an entire piece of music. Just like in Species Counterpoint, we start with 1 and end with 5-1. Because this progression acts as a bookend, it also is the basis for different cadences. Cadences mark the harmonic arrival at the end of a phrase. They are preceded by a cadential progression, which is a series of chords that can lead to a cadence. It's important to note that cadential progressions are often incorrectly called cadences. They lead to cadences, but cadences are only the arrival of a certain harmony, not the collection of harmonies leading up to the cadence. Cadences are integral to tonal music because they provide goals for phrases and drama when they are voided or delayed. Cadences act like punctuation marks with varying degrees of conclusiveness. Let's look at a few of the basic cadences that you will encounter in your analyses. The first cadence type is the Perfect Authentic Cadence, or the PAC. A Perfect Authentic Cadence occurs when 1 arrives after 5, with DO or scale degree 1 in the melody. Of all the cadences, the Perfect Authentic is the most conclusive. Here's what it sounds like. The second cadence type is called an Imperfect Authentic Cadence. This cadence type occurs when the arrival of 1 after 5 with MI, ME, or SOL in the melody. This differs from the Perfect Authentic Cadence, which is perfect because DO is in the melody. Here, scale degree 3 or 5 will create an Imperfect Authentic Cadence. The IAC is less conclusive than the PAC, but it still features 1 as the arrival, which makes it a strong cadence type. Here's what it sounds like. The final cadence type we're going to discuss is the Half Cadence. The Half Cadence marks the arrival of 5. Now, 5 might occur in many places in the phrase, but it's only a Half Cadence when 5 is reached at the end of a phrase. Of the three cadence types that I've discussed, the Half Cadence is the least conclusive, because it concludes on a chord that's associated with tension and drama, whereas the other two cadences close on a chord of resolution. Here's what a Half Cadence could sound like. Let's see a cadence in action in this excerpt from Schubert's Six Musical Moments. Listen to the excerpt and see if you can hear the cadence at the end of the phrase. The cadence at the end features a suspension above 1 in the bass in the second-to-last measure. It's important to know that cadences are intensified by suspensions, not delayed by those suspensions. Once the suspension has resolved, we notice that we have a Perfect Authentic Cadence because of Scale Degree 1 in the soprano. We can also add a 7th above Scale Degree 5 to create even more tension and excitement. Listen to this example from The Beatles' Twist and Shout. The singers build the dominant 7th chord one note at a time, and when they get to the final note, the 7th, the chord has a dissonance and a tension to it, making it the perfect contrast to the resolution of 1 that comes immediately after it. 5-7 is truly the opposite of 1. To write 5-7 in your part writing, you should know that 1-5-1 harmonizes melodic figures around members of the tonic triad, using passing and neighbor motions, and sometimes incomplete neighbor motions. You will explore more part writing harmonizations in class, but let's cover some basics here. The 7th of the dominant 7th must resolve down by a step, no matter which voice it is in. This is just like in 4th Species Counterpoint, when we add a dissonance that must be resolved down by step. Scale Degree 7 must resolve to the tonic when it is in an outer voice. Here's what this progression sounds like. The 7th of the dominant 7th chord and Scale Degree 7 are both tendency tones. It's easy to confuse them because they both contain the number 7, but try to keep them straight by remembering that the 7th must always resolve down, and Scale Degree 7 resolves up. Scale Degree 7 may be frustrated, that is, unresolved, in an inner voice. It generally resolves down to Scale Degree 5 in such cases. Here's what this top example sounds like. The 5th of the dominant 7th can also be omitted for smoother voice leading. Notice in the bottom example that C is omitted from the chord, and the top voices move by step to a I chord. Here's what the bottom example sounds like. As I said before, you will see more examples and get more practice writing the V7 in class. This video covered a lot of ideas that stem from the basic chord regression I-V-I, because it is an important progression in tonal music and the basis for cadences. We learned that cadences are harmonic arrivals which provide drama and have varying degrees of conclusiveness. Those cadence types are perfect authentic, imperfect authentic, and half cadences. Through a Schubert example, we discover that suspensions do not delay cadences, but instead intensify cadences. Finally, the addition of the chordal 7th to the V chord adds tension, but it requires careful treatment, as it is a dissonance. That's all for now. Thank you for watching!