Disadvantages of grand staff notation
1) what notes to play
Note Finding
Conventional sheet music is more like a code than a map. Lines and spaces translate nothing like a keyboard. The treble and bass clefs are mirror images of each other rather than copies of each other. Also, any given note must be determined to be either "on" or "between" lines. This is an even/odd-like system housing seven steps per octave. These factors make it so that each note is visually unique (i.e. "E" in one octave looks nothing like the "E" of any other octave). Therefore, each note has to be learned and recognized individually.
The lines and spaces of the grand staff only account for 3 of 7 octaves (2.83 of 7.3). This makes the majority of the keyboard one big exception, requiring things like clef reassignments, ledger lines ( - ), and octave displacements (8ve).
Topography
Lines and spaces are not topographic; they only locate the white keys. The black keys are governed by a wildly inefficient system of alterations to the white keys, largely to blame for prohibiting a student's musical exploration. These alterations are indicated by a "key signature": a pile of symbols at (and only at) the far left of each clef, situated on and between lines. Usually a line or "space" with a corresponding symbol will have its notes replaced by a black note at each occurence. A most curious exception is when one white note is to be replaced by another white note, thus frustrating the otherwise exclusive and simplistic idea: symbol designates black note.
Exceptions, reiterations, or additions to a key signature show up as individual symbols, or "accidentals", the amount of which determine the degree to which they defeat the simplicity that key signatures strived for. The student must be able to understand the various accidentals as they show up, accurately translate them by altering the printed notes by the correct amount in the correct direction, and mentally "carry" each throughout its measure.
Note Reading:
As the student becomes more fluent in placing notes, the rotation not only becomes more difficult, but because the notes jet off horizontally, the flow of the piece is interrupted every page width by a line break. This makes skipping a line and even losing your place in music all too common.
2) when to play them
Precision
Anticipation suffers quite a lot with conventional sheet music. Notice that two simultaneous notes of a diatonic step (third measure, left hand) have to use x-axis juxtaposition. Absent accidentals, this sets a limit on the amount of note-scrunching available in quick passages. When that limit is reached for a particular measure, then its bar lines have to be drawn farther apart. Irregular intervals along an X axis isn't good.
The bar lines divide beats (i.e. beat 4 and beat 1 of the next measure), so there is a metrically nonexistent gap between every bar line and the beginning of each measure. This makes it so that electronic, scrolling displays have to either spill over the bar line or jump once each measure.
Note Values
While bar lines are shown, beats themselves are never shown, and are only distinguishable if certain frequently disregarded principles of metric placement are followed. Subdivisions of individual beats reference a tiered system of beams, flags, dots, and ties of both notes and their counterpart rests. The complexity of each tier necessarily limits the student's repertoire until specialized study of the next rhythmic tier qualifies the student to advance. Otherwise, so many note values are likely to be played identically, or even interchangeably. Both are incredibly annoying.
The worst annoyance, in my opinion, is that Note durations don't stretch.
Ties are entirely distracting because they confuse two completely different operations: placing a new note and monitoring some preexisting count queue.
Flow
Many pieces rely only on European translations like "lento" and "rubato" to indicate the general speed, or "tempo", and its alterations. This is just one more thing that needs to be taught in order to keep the student from peeling out in slower pieces.
3) how to play them
Dynamics
Passage dynamics don’t refresh, while individual note dynamics have only one contrasting “accent” or “sforzando” to indicate “louder than the rest”, thus neglecting a myriad of other important stylistic possibilities.
Misc
Rests should never have existed. After all the 3 beat rests I heard in 4/4, I say they never really worked anyway. Measure numbers go missing, "simile" passages use shorthand, exact repeats require even more European translations with their strange counterpart signs, articulations use even more conventions like dots & dashes, and all kinds of other figurations like trills, arpeggios, and turnarounds reference even more abstract principles.
Summary
It appears to me as fact, rather than opinion, that conventional sheet music is imprecise, inefficient, and, by this, renders difficult the simplest desire to just read music. Because of this, I have been working with a new, interactive notation I call "piano roll". My estimates show it to be about 20 times as efficient as conventional sheet music, all things considered. Samples can be seen on YouTube under my "Piano Roll" series.
copyright 2007, Steven Wilson