An introduction to various types of alternative notation systems. For another overview of the same systems see the Gallery which lets you sort and filter them by their features.
Similar notation systems are presented together here and elsewhere on the site. They are grouped by the interval between neighboring staff lines (line spacing) and then by the number of staff lines per octave. A final group presents 7-5 systems, in which the intervals between lines are less regular. Within each group, systems are ordered by the similarity of their features, not necessarily by their invention date.
A number of notation designers have used a five-line chromatic staff with one ledger line. This is a total of six lines spanning an octave, each spaced a whole step apart. The ledger line allows multiple one-octave staves to be "stacked," placed contiguously for greater pitch range. In many cases these staves look exactly like the traditional staff (which would cause confusion), but some systems introduce bold lines or change the position of the ledger line.
Several systems have a four-line staff alternating with two adjacent ledger lines. They are similar to the five-line staves (above), but they are slightly less visually dense (or "busy"), and require more ledger lines. They are also less likely to be confused with traditional notation. One system goes further with only three lines that alternate with three ledger lines per octave. Signs such as dynamic markings can be written in the space created by the ledger lines, even when multiple staves are stacked contiguously.
If there were six standard lines per octave, it would be very difficult to discriminate pitches when reading music on two contiguous staves. So some inventors substitute bold or dashed lines in the place of some of the normal lines. This permits the use of six lines per octave without sacrificing the ability to "stack" multiple staves contiguously for a greater pitch range.
In these systems the lines are either a whole step or a major third apart. The bold lines help the eye discriminate between different lines, facilitating pitch identification. An alternating 6-6 notehead 'color' (hollow or solid noteheads) makes it even easier to differentiate between pitches. See the Using Notehead Color for Pitch for more about this strategy and how it affects rhythmic notation.
Lines spaced a minor third apart provide a slightly less dense appearance than lines spaced a whole step apart. Between the lines are two space-notes at different elevations. There is a repeated line-space-space pattern, three basic note positions that occur four times per octave. (Rather than a 6-6 or 7-5 pitch pattern, this could be called a 4-4-4 pitch pattern.) Three standard lines alternate with a ledger or bold line which allows for identification of the lines when stacking staves contiguously for greater pitch range.
These systems achieve a less dense appearance through lines that are spaced a major third apart. Between the lines are three elevations where notes are placed. One of the three lines per octave is either bold or dashed to allow for identification of the lines when more than one staff is stacked contiguously for a greater pitch range. Some systems use hollow and solid noteheads to help differentiate between adjacent pitches.
These systems are similar to those with three lines, a major third apart (above), only they have a ledger line (instead of a bold or dashed line) for their third line per octave. This gives them an even less dense appearance and allows for easy identification of the lines when staves are stacked contiguously. Lines spaced a major third apart have three note elevations in the spaces between the lines. Some systems use hollow and solid noteheads to help differentiate between adjacent pitches.
These systems are like vertically compressed versions of those that have two lines, a major third apart (above). They require less vertical space by introducing a second notehead shape that fits more compactly between adjacent lines, while still keeping the centers of the noteheads evenly spaced on the vertical axis. These shapes (and in most cases hollow and solid noteheads) help to discriminate between adjacent pitches.
Some systems have two lines per octave, evenly spaced at a half an octave apart (one tritone or six half-steps). Bold, dashed, or ledger lines are used to allow identification of lines when multiple staves are stacked contiguously. One system uses only one line per octave, giving it the least dense appearance of any system, but it also uses the most ledger lines, with 7 of the 12 pitches requiring them. Some systems use hollow or solid noteheads or shaped noteheads to help differentiate between adjacent pitches. (Also see Equiton, which has one line per octave but lacks pitch-proportionality.)
Many chromatic staves have lines spaced either a whole step apart, or some multiple of a whole step (a major third, a tritone, or an octave). These systems follow a different principle instead. The lines of these staves have an irregular spacing that highlights the 7-5 pitch pattern, by putting the diatonic notes of the C major scale either in spaces or on lines and ledger lines.