And the Representation of Pitch
Clairnote SN has a "chromatic" staff that gives each of the twelve notes of the chromatic scale a distinct vertical position on the staff. Notes appear on a line or in one of three positions in the space between the lines: "sitting" directly above a line, "hanging" directly below a line, or on a ledger line half-way between two lines.
On a chromatic staff the vertical distance between notes is always proportional to their difference in pitch. This helps provide a clear and consistent representation of the interval relationships between notes. The pattern of line notes and space notes (the 6-6 pitch pattern) also helps to make these interval relationships more apparent.
6-6 Pitch Pattern
An important aspect of Clairnote SN's representation of the twelve notes of the chromatic scale is that it provides a visual distinction between the two whole tone scales. (A whole tone scale is a series of notes evenly spaced a whole step apart.) One is a series of 6 line notes, and the other is a series of 6 space notes. This is known as a "6-6" pitch pattern.
These two whole tone scales combine in a regularly alternating pattern to form the chromatic scale.
This regular pattern in the representation of pitch means that intervals, scales, and chords have a consistent appearance regardless of the current key or their vertical position on the staff. This is known as isomorphism (the syllables "iso" and "morph" meaning "same" and "shape").
For example, all major scales start with three line notes, followed by four space notes (or vice-versa). All minor thirds are a line note and a space note, while major thirds are two line notes or two space notes. What you see always corresponds with what you hear.
The benefits of the 6-6 pitch pattern can be understood by analogy with the distinction between odd and even numbers. Odd and even numbers help with counting and determining the relationship between two numbers. In a similar way, a 6-6 pitch pattern makes the interval between two notes easier to perceive. And that makes it easier to see and understand the contours of scales and melodies and the patterns that make up chords and harmonies.
The Staff's Line Pattern Repeats With Each Octave
The groups of two lines that make up the staff always represent the note E and the note G-sharp (or A-flat). The repeating line pattern corresponds with the repetition of the octave. That means every octave has the same basic representation on the staff. Notes an octave apart always fall on "the same" line or space, making it easy to identify notes. What looks like a "missing" middle line is actually an "internal" ledger line that represents C. Additional "secondary" internal ledger lines represent D, F-sharp (or G-flat), and A-sharp (or B-flat).
Staves Spanning More Than Two Octaves
The default Clairnote SN staff spans two octaves (from the first C ledger line below the staff to the first C ledger line above it). Staves with greater pitch ranges can be used as needed, depending on the range of the music and/or the instrument. A one octave staff could even be used, for example when teaching younger children.
Piano music can be written on a continuous four-octave Clairnote SN staff like the one shown above, or on a "grand staff" with two separate staves that span two octaves each, one for the left hand and one for the right, as in traditional music notation.
Music for guitar can be written on a three-octave Clairnote SN staff. The notes are played as written. (Music for guitar in traditional notation is typically written in treble clef, but the notes are played an octave lower than they are written.)
If the music extends above or below the staff then ledger lines are used as in traditional notation. To avoid having too many ledger lines the Clairnote SN staff can be temporarily extended up or down by an octave or more.
How Does Learning the Clairnote SN Staff Compare with Learning the Traditional Staff?
Consider this (admittedly) overly simplistic quantitative comparison, that disregards key signatures, accidental signs and other factors. Given a single clef on a standard staff there are only seven staff positions per octave to learn. However, there are roughly thirteen staff positions to learn (five lines, four spaces, plus one space and one ledger line above and below the staff).
On Clairnote SN's staff there are twelve note positions per octave rather than seven, but because the staff's line pattern repeats with each octave, those twelve positions are the only ones to learn. So the number of staff positions to learn is about the same as learning to read in one clef on the standard staff.
Of course, the thirteen positions on a standard staff are different for each clef. Someone learning to play piano has to read treble and bass clefs at the same time, which is twenty six unique staff positions. (See also Clefs.)
Clairnote SN's "Vertically Compressed" Chromatic Staff
One of the only disadvantages of a chromatic staff is that it takes up more vertical space on the page compared to a traditional "diatonic" staff because there are twelve notes per octave rather than seven. The distance between any two given notes becomes greater, both physically and symbolically with the number of intervening staff positions. This can make it harder to easily recognize larger intervals and tell them apart.
Clairnote SN addresses this by spacing staff lines a major third apart and through "vertical compression" of the staff, allowing vertically adjacent notes to overlap to a greater extent than they do on a traditional staff. The consistent (6-6) pitch pattern of line notes and space notes helps by making it easier to differentiate between notes.
The following image shows three different staves with the same one-octave harmonic intervals (E to E and F to F).
On the "uncompressed" chromatic staff (far right) the adjacent notes overlap the same amount as on a standard staff (far left), so an octave spans 12/7 (or 1.714...) times as much space as an octave on a standard staff. (Because there are 12 staff positions per octave instead of 7.) On the compressed Clairnote SN staff adjacent notes overlap more, resulting in an octave that's only 9/7 (1.285...) times the size of an octave on a standard staff.
In more detail, the distance between the midpoints of adjacent notes on the compressed Clairnote SN staff is 3/4 of what it is on a standard staff. The relative size of the octave is thus 3/4 (the distance between adjacent notes) times 12/7 (the ratio of the number of notes per octave on the staff) which is 36/28 or 9/7.
Here is another image that adds a hypothetical chromatic staff that has been compressed further (too far...) so that an octave spans the exact same vertical extent as on a standard staff.
This hypothetical staff is still physically larger than the standard staff even though an octave spans the same physical distance. This is because the Clairnote SN staff covers a greater pitch range from its bottom line to its top line, from E to G-sharp (16 semitones). The standard staff spans from E to F (13 semitones) in treble clef, or G to A (14 semitones) in bass clef. The image shows that part of the larger size of the standard Clairnote SN staff is due to this greater pitch range of the Clairnote SN staff. (Note that the larger range of the Clairnote SN staff means that there is less of a need for ledger lines.)
In short, the vertical compression of the Clairnote SN staff allows it to take up less space on the page. That makes music easier to read, especially larger intervals. (This "vertical compression" approach has also been used by John Keller in his Express Stave system that he introduced in 2005, and by Jan Braunstein in his Chromatic Lyre Notation. Some notation systems like Twinline and TwinNote use different notehead shapes as another way to achieve a vertically compressed chromatic staff.)
Next, check out how easy it is to see the interval patterns of scales in Clairnote SN.