This experimental system combines a diatonic staff with a 6-6 solid/hollow note head pattern. (“DS” for Diatonic Staff, “66” for 6-6 note head pattern.)
The 6-6 solid/hollow note head pattern helps musicians identify intervals and read music relatively (by interval). It also reminds them when notes are sharp or flat due to the key signature (or accidental signs).
The staff’s line pattern ‘cycles’ every two octaves. You can think of it as a 6-line staff except the third line from the top is a ledger line. Two separate groups of two and three lines are arguably easier to learn and to read than a staff of six. Also, the groups of lines are inversions of each other since both are centered on the note G. (The middle line of the three line group is G, and the space between the two lines of the two line group is G.) This inverse relation helps with learning and remembering the lines and spaces of the staff.
The line pattern also follows the traditional treble and bass clefs. The lower part of the staff (the three line group) is the same as the bottom of the treble clef staff and the upper part (the two line group) is the same as the top of the bass clef staff. This means the notes of the DS66 staff covers the notes of the bass and treble clefs, and thus can be used as a direct replacement with music written on those traditional clefs. The similarity with the traditional staff and clefs also makes it easier to learn DS66 along with the traditional system.
DS66 offers a lot of continuity with the traditional system, while addressing some of its shortcomings. Traditional key signatures and accidentals are used. Traditional rhythm symbols are used except half notes are indicated by double stems.
This system is similar to Classic Nydana (http://nydana.se/classic.html) except it prioritizes consistency of interval appearance over consistency in the appearance of individual notes. Thus it maintains a consistent line-space alternation and cycles every two octaves rather than every octave. (Classic Nydana has two adjacent space notes, A and B, to achieve a diatonic staff that cycles every octave.)
Originally introduced by Paul Morris in this post on the MNP forum (google group) in March 2017.