So based on that argument then where does that leave the chromatic scale, where does it leave the semitone as a supposed unit in musical theory? So lesson five is gonna be concerned with these two issues, what's the status in biological terms of the chromatic scale and the semitone? And, again, let me just remind you that these 12 intervals, 13 notes of the chromatic scale, are each separated by a semitone interval. That semitone interval depending on the tuning system that you use, again we talked about the Phrygian, just intonation, equal temperament. The semitone has a little different actual physical size, but in each of these tuning systems, there is something that's defined as a semitone. The interval between each of these 12 steps in the chromatic scale. But, based on the argument in lesson four, the chromatic scale in the semitone don't really exist. First of all, let's take the limit of 12 notes in the chromatic scale. That limit is just an organizational principle. There's no limit in terms of a biological explanation of division. The visions of the octave, why you should be limited to 12 notes. You're not, you can make as many divisions as you'd like. But remember from what I just said in lesson four that the more divisions that you make, the less and less the vocal similarity. And after you've made even seven interval division, eight note divisions in an octave. You're already at the tipping point and rapidly going to loose vocal similarity. And that's why in fact music composed with more then seven intervals is not appreciated as popular. What does that mean about the chromatic scale? Well what it means is that these 12 notes are not really notes that form a scale that can be played using all 12 of those notes. Composers that have tried that in atonal music or 12 tone music, and there have been a bunch, particularly in the early 20th century, Berg, Webern, Schoenberg, and others have tried to make music, have made music, and it's music that is appreciated in some quarters, using equal emphasis on all 12 notes. But, for most of us, that music is not easily appreciated because, again, when you use all 12 notes equally expressed in a musical composition, you are losing the vocal similarity and using it's attractiveness to the average listener, and relegating the appreciation of atonal music and tone music and other forms like that to a very specialized audience. >> In this video, we'll demonstrate the difference between Tonality and Atonality. The two pieces we'll be contrasting are 2 Lieder, which are classical voice pieces sung in German with piano accompaniment. Both are composed by Alban Berg and both have the same lyrics and title [FOREIGN]. Check the course site for a translation of the poem. You'll hear the tonal version first, which was composed in 1900. Notice that you'll expect the pitches in the music to progress in a certain way even if you aren't the most experienced musical listener. In particular, note the sense of resolution at the end of the tonal piece. This phenomenon shows how familiar the tonal idiom is, compared to the atonal. However, even though the piece is in C major. Berg selectively uses notes outside of the C Major scale. In fact, nearly all of the notes in the chromatic scale are present in this piece. Although, they are used less frequently than the notes in the C Major scale. Emphasizing pitches in the key or scale more than pitches that are not in the key or scale is fairly representative of most tonal music. With these characteristics in mind, listen to the tonal version of Schliesse mir die Augen Beide. [MUSIC] We'll play the atonal version next. Berg composed this piece in 1925 using the 12 tone method, which means that each pitch in the chromatic scale occurs as often as all of the others. Note that it is quite difficult to predict what will happen next in the piece. The music sounds quite unfamiliar to those that aren't used to listening to atonal music and probably even to those that are. Also note the wide vocal and piano range of the piece as well as the odd vocal leaps. This piece is by no means easy to sing. These factors contribute to a lot of tonality in this work. In other words, it's impossible to pick out a tonic or find a word do in the Do-Re-Mi scale would be in this piece. However, that doesn't mean that the piece is entirely unpleasant sounding. The 12 tones are organized in a very specific way and very skilled hands. Here's his atonal setting of [FOREIGN]. [MUSIC] >> So the chromatic scale is not really a scale in the sense of a set of intervals that can be played with equal emphasis the way you can play a pentatonic scale or heptatonic scale and make wonderfully popular music on that basis. It's an organizational principal. It is, as I said, the superset from which notes are drawn. As an organizational principle, it has great value, but as a musical scale per se, it really doesn't. And of course, it raises problems for the tuning systems that we talked about. And let's make the point about the semitone as well. The semitone like the chromatic scale, is an idea, a concept that has no theoretical basis as a physical reality. Depending on the tuning system, you remember that the semitone ranges around six or seven percent as expressed as an increment over the preceding tone. But, based on what I've said in this lesson and the last, there is no physical definition of a semi-tone that applies logically. If we take a biological explanation of scales as the one that makes sense. And because there's no limit to the number of tones that in principle, you can put into the division of an octave, there's no defined semitone. The semitone ranges in size, depending on how many divisions you wanna put into the octave and that number division is determined by the eventual loss of vocal similarity. So the semitone, like the chromatic scale, is really a concept that exists as an idea in music theory, but it doesn't exist really in terms of a biological reality when you take harmonic overlap as the basis for a natural scale. So whether you use equal temperament or any other tuning system, the semitone, it has didactic and practical use, but it has no definition in biological terms that make sense in terms of something that actually limits the music that we play, other than in the eventual loss of vocal similarity.