Seventh Chords and Their Symbols

Hello everybody! This is Dr. Meier with a video on 7th chords and their symbols. A 7th chord is a chord with four notes stacked in thirds. Just like a triad, it has a root, third, and fifth, but also an added interval of a seventh above the root. The 7th chord contrasts and complements the triad in tonal music, and acts as part of the tension and release and ebb and flow of the music. Just like the triad, the 7th chord can be distinguished by four characteristics. The root, quality, position, and voicing. There are new types of qualities and positions because of the added member of the 7th chord. The root of the 7th chord is the bottom note when the chord is stacked in thirds. There are more notes to deal with here, so make sure that your chord is stacked in thirds before naming the root. The quality of the 7th chord depends on two things. The bottom triad quality, and the quality of the 7th above the root. Now there could be more combinations than those shown here, but these are the 7th chords that are commonly found in tonal music. Let's start on the left side. The top 7th chord has a major triad on the bottom, and a major 7th above the root. This 7th chord's quality is called the major major 7th. Below, the other 7th chord with a major triad on the bottom has a minor 7th above the base. This chord's quality is a major minor 7th, or a dominant 7th. It's sometimes notated by an excess 7 to show that it's dominant. The dominant 7th only occurs in any key one time on scale degree 5, and is a very important 7th chord that will be explored in later detail later in the semester. Moving over one column to the right, we have a 7th chord with a minor triad on the bottom, and a minor 7th above the base. This 7th's quality is a minor minor 7th. Notice that there's no minor triad with a major 7th above. That's one of those chords that doesn't appear often in tonal music. Next, we have a diminished triad with a diminished 7th above. This stack of minor 3rds is called a fully diminished 7th chord, and is often notated with a small degree symbol next to the root or Roman numeral. Below, there's a diminished triad with a minor 7th above. This 7th is called a half-diminished 7th, and is notated with a slash through the degree symbol to indicate half. Finally, we have the augmented triad with a major 7th above. This 7th is called an augmented 7th, and is often notated with a plus sign to indicate that it's augmented. Listen to the triads in the order that I discussed them. Practice identifying the quality of the two triads here. Remember to look at the quality of the bottom triad, as well as the quality of the 7th above the root. For the left side, you should have gotten a minor triad with a minor 7th above. This is a minor minor 7th, and is labeled as an A minor 7th in this case. On the right, you should have found a major triad with a major 7th above. This is a major major 7th, and is labeled as a major 7th in this case, F major 7th. Just like the triad, the 7th chord can be inverted to have any member of the chord sounding as the bass. With the 7th chord, there are four positions possible. Root position, where the root is the bass. First inversion, where the third is the bass note. Second inversion, where the root and third are above, and the 5th acts as the bass. And finally, third inversion, where the 7th of the chord is the lowest sounding pitch. We can use figured bass to describe the position of 7th chords, but it's a little more involved than it was with the triad. Plus, we have to distinguish our figured bass to describe the 7th chord, instead of what we use for the triad. So, in root position, there is a 3rd, a 5th, and a 7th above the bass. So if we describe every interval with our figured bass symbols, it would look like this. 7, 5, 3. But just like root position with triads, the 5 and the 3 are commonly left out. So your figured bass for a root position 7th chord would look like this below, with just a 7. First inversion has a 3rd, 5th, and 6th above the bass. Again, if we describe every interval, we could show 6, 5, 3 below the bass. However, a 3rd appears in nearly all of these 7th chords, so it doesn't distinguish this one from any of the others. So the 3rd is left out of the figured bass, so it would look like this below, with just a 6 and a 5 figure to indicate first inversion. Second inversion features a 3rd, 4th, and 6th above the bass, and here below is all of the present intervals. However, the distinguishing intervals of second inversion are the presence of both a 3rd and a 4th, so the 6th is often omitted from the figures, and would look like this below, with just a 4 and a 3. Lastly, a 3rd inversion has a 2nd, 4th, and 6th above the bass. This time, the distinguishing intervals are the 2nd and the 4th, so those are the intervals represented here in the figures. Sometimes, even the 4th is omitted, because 3rd inversion is the only 7th chord with the interval of a 2nd in it. A helpful way to remember the different figured bass symbols for 7th chords is to think of the symbols in order, so 7, 6-5, 4-3, and then 2. Let's practice identification and construction. On the left, identify the quality and inversion of the given 7th chord. On the right, construct the 7th chord with the given key signature and figured bass. Pause the video if you need more time. You should have gotten a minor minor 7th with G as the root, so G minor 7, and it's in 1st inversion. On the other side, you should have written a 3rd, 4th, and 6th above the given E to create a major minor 7th chord with A as the root, so A7, in 2nd inversion. Lastly, like triads, 7th chords can be voiced in many ways, with many different doublings, as long as there are the 4 tones that make up the 7th chord. Below, we have two G dominant 7, one in root position and one in 1st inversion. Next to that, we have two A minor 7th chords, one in root position and one in 1st inversion, each with different voicings. The take-home messages in this video are that 7th chords provide contrast to triads and have four distinguishing characteristics, the root, quality, position, and voicing. The quality of 7ths depends on the quality of the bottom triad and the quality of the 7th above the root. We use figured bass symbols to describe the position of the 7th chord with relation to the bass note, with the symbols 7, 6-5, 4-3, and 4-2. That is all for now, thanks for watching!