In this episode I’m going to explain the interval layout of SoundPrism. While melody oriented instruments like the piano or Animoog are well suited to explain the names of intervals, SoundPrism’s strength is to reveal the tonal character of intervals.
SoundPrism tone layout
Before I start to explain intervals in SoundPrism let’s have a short look at how SoundPrism works. In the following figure the musician taps the instrument at the touch point (1). From this point a semitransparent rectangle (2) is created, that is the so called pitch selection area. Inside this rectangle there is a white segment (3). This segment represents the tone that is actually played. To understand that you need to know that in SoundPrism only certain segments contain tones, which is the white one currently in the picture below. Fortunately you need not to hit these segments exactly. It is enough if it are covered by the pitch selection area.
The next figure shows that every column contains exactly one tone. From column to column the C-major scale c, d, e, f, g, a, b and c arises. To get another scale you can use the key up and key down buttons (not shown here).
In horizontal direction SoundPrism orders tones in the same way the piano or Animoog do. But in addition to that SoundPrism also assigns a vertical position to every tone. This position makes intervals and chords appear in a way that important musical properties are revealed. Let’s have a look at how this is done for intervals.
The octave is the most consonant interval. The reason for this is, that both tones of the octave have a frequency ratio of 1:2, for example 440 and 880Hz. Another reason for the conciseness of the octave is the overtone series: The first two overtones create an octave. Two tones with a distance of an octave are easily perceived as one tone. Because of its importance the octave got a very prominent place in SoundPrism: To play an octave you simply need to play two horizontally neighbored tones. This is shown by the following figure.
Fifth and fourth
Behind the octave the fifth is the second most consonant interval. The frequencies of the tones have an ratio of 2:3. Also in the overtone series the fifth is the second interval after the octave. That is the reason why we easily perceive one tone instead of two when listening to a simultaneously played fifth. The following figure shows a fifth in SoundPrism. To play a fifth you simply need to skip one row.
The fourth is the complementary interval of the fifth. Fourth and fifth sound very similar. SoundPrism acknowledges that similarity by assigning the same playing pattern to complementary intervals: You can see this by comparing the previous and the following figure: The gesture for playing a fourth is the same as for playing the fifth. The only difference is, that you need to move your fingers slightly in horizontal direction.
Third and sixth
Compared to fourth and fifth the third is not less important. It is also part of the early overtone series. In addition to that the third is the foundation of the important major and minor triads. This was the reason why we decided to design SoundPrism such that the third is the interval most easy to play. As shown by the next figure, you can simply play a third by touching two neighbouring rows.
The sixth is the complementary interval of the third. Again SoundPrism acknowledges that by assigning the same playing pattern to third and sixth. Simply move your finger to the left or to the right to transform a third into a sixth.
Second and seventh
The second is the most dissonant interval. SoundPrism outlines this tension by arranging the tones in a greater vertical distance. The melodic closeness of the second is represented by the horizontal closeness: If you look closely at the following figure you will see, that the two active tones occupy neighbored columns. Thus to play a melody you just need to find the tone in the next column.
The seventh is the complementary interval to the second. Again it can be played by moving the pattern of the second horizontally.
Opposite to the piano or the Animoog keyboard SoundPrism arranges tones in such a way that interval relationships become clear. Every interval has a specific pattern that can be easily remembered and applied:
- The tones of the consonant octave are in horizontal neighborhood. The tones of the third and sixth are in vertical neighborhood. These intervals are the foundation of chords.
- Fourth and fifth are outlined by the design of the rows: neighbouring dark or neighbouring bright rows in SoundPrism contain the tones of fourth and fifth.
- The dissonance and tension of the second is outlined by the great vertical distance of the interval tones. The melodic importance of the second is emphasized by assigning the tones of the second in neighbored columns.
- The affinity of complementary intervals is outlined by assigning the same playing pattern to these intervals: To play a fourth or a fifth for example you can use the same gesture.