Now that I have covered the ideas of pitch and rhythm as they relate to the Korean music perspective, the next topics to be covered are modes, tonal centers, and cadential phrases. In general, it is understood that traditional Korean music is pentatonic in nature. There are notes outside of the pentatonic scale in some pieces. However, these notes are not consistent enough to justify the production of a true hexatonic or heptatonic scale. There are two modes that are most common in the Korean repertoire. The first being a do-mode known as p’yonbjo, and containing the tones: do (c), re (d), fa (f), sol (g), and la (a). This mode is perceived in the western ear as being major in character. The second is a re-mode and is known as kyemyonjo. This second mode contains the notes: re (c), fa (e flat), sol (f), la (g), and do (b flat). It is minor in its character, as perceived by western ears. I use the phrase “as perceived by western ears,” because in the Korean conception of tonal center and mode characteristics there is not necessarily a major or minor. At least not in the western sense.
Although there are two primary modes in the Korean tradition, there is a third mode which is in common use and is Chinese in origin. This mode is a heptatonic fa-mode with the inclusion of two auxiliary notes. This scale is actually the primary scale of Chinese musical theory. In addition, this scale along with many songs and musical ideas were adapted by the Koreans. Even though they are Chinese in origin they became thoroughly integrated into the Korean idiom of music.
Cadences in music of the Korean traditional repertoire are quite simple. Especially, when compared with the European classical theory of musical cadences. In western music there are many possible cadences, some of which are more common and others more remote.  In traditional Korean music, however, there is only one standard cadence. The standard Korean cadence is simply a descending stepwise motion ending on the tonic note of the mode. Because Korean musicians have imported and adapted many Chinese pieces of music, one might assume that they have also adapted the Chinese cadences as well. Chinese cadences are more widely varied than that of the Korean tradition, and you might expect to find this reflected in the Korean adaptation of Chinese music.  In all actuality, what you find is that all Chinese cadences, except for one, have been altered to better fit the Korean vernacular. The single exception to this would be found in the previously discussed heptatonic fa-mode of Chinese origins.
Having now covered the most basic principles of traditional Korean music theory, now would be a great time to recap beginning with the Korean idea of pitch. To a Korean musician, pitch is a dynamic part of the musical expression which encompasses ornamentation in the forms of vibrato, slides, appoggiaturas, and other means. Um, which means sound, is pitch and can be thought of as a gesture rather than a single note. Rhythm to a Korean musician is thought of as patterns of long and short rhythmic phrases which combine to make larger rhythmic phrases. Some as long as 24 beats. Compound rhythms are commonly found.
The Korean sense of tonality is one that centers on a pentatonic frame work with two primary modes. One being “major” in character and the other “minor.” The ending of a melody or a cadence is one of a simple step wise line with the final note being the tonic of the mode. The only exception to these principles would be the fa-mode of Chinese decent.
In conclusion, Korean music has a deep and long tradition.  The sounds we hear seem strange to western ears. It is my hope that this wonderful art form will gain more appreciation through this exploration. Often people cannot enjoy something because they feel the cannot understand it and it is somehow wrong because it is different from what they normally hear. Instead, I encourage you the reader to embrace this difference and enjoy the great variety that is available to us.

Now that we have sufficiently covered the concept of pitch, as it is within the context of the Korean tradition, I will move on to rhythm. Korean musicians refer to the rhythmic patterns found in traditional Korean music as changdans. This literally translated means “long and short.” These changdans include regular and irregular rhythmic patterns. Even regular patterns, however, can change by grouping beats into different sets of rhythmic patterns. For example, a 16 beat phrase might be grouped into beats 5+3+5+3, or perhaps 2+3+3+2+3+3. The idea of changdans can also be applied to the unit of rhythmic groups within the first and last beat of each rhythmic type. Therefore, it could be considered a rhythmic set of 2 beats or more. An example of this could be two rhythmic sets of 8 beats, which combine to make a larger changdan of 16 beats. Those two smaller rhythmic sets could also be divided into sets like this: (3+3+2)+(3+3+2); thus, creating a smaller changdan within a larger one.
Although, rhythmic patterns are not at all limited to beat sets of 16. There may also be sets of 20 divided; thus, (6+4)+(4+6)=20. Sets of 10 beats, which would look like this: (3+2)+(3+2)=10, and beat patterns may also exceed 20. However, an exploration of the complete Korean rhythmic system is beyond the scope of this exploration. Therefore, I will move onto a quick word on performances of chagdans.
Often a changdan of large proportions such as a 24 beat cycle may begin slowly. Then gradually accelerate and build to a faster tempo. In a case where there is a shorter cycle, there will often be a metrical series such as 20/4, 10/4, 6/4, and 12/8. In exceptionally long beat cycles the metric modulation may be as follows 24/4, 12/4, 4/4, and 2/4. The characteristics of expansion and reduction, which are part of the formal structure of the Korean rhythmic concept, yields a great deal of flexibility and richness. It is a deep part of the definitive sound of the music.