We have seen that writing drones in the same way as other sounds of specified pitch can create confusion at moments where the pitch of the melody and drone coincide (see Melody with drone). The same applies when writing two or more melodic lines that are performed simultaneously. If the melodic lines overlap in pitch, the notation needs some means of disentangling them.

A musical texture involving more than one melodic line at the same time is known as “counterpoint.” Examples would include a group improvisation in jazz, a Javanese gamelan performance, a great deal of Western classical music (especially from before about 1750), and a simple “round” such as “Frère Jacques” (also known as “Are You Sleeping?”). The individual melodic lines in a piece of counterpoint are called “voices” (even if they are performed on an instrument).

In counterpoint, the different voices are usually arranged so that, most of the time, they are sounding different pitches that form pleasing harmonic combinations. However, there will often be moments in which more than one voice is sounding the same pitch. If notated using the standard symbols for sounds of specified pitch, it may be unclear that these “shared” pitches belong to more than one voice, since they will look the same as other pitches. When the different voices move on from a shared pitch, it may also be unclear which voice is which - for instance, whether each voice “rebounds” in the direction from which it approached the shared pitch, or continues in the same direction so that the voices “cross” in pitch.

An example in which two separate pitches cross over and so it is uncertain how these two separate pitches are to be interpreted.

For these reasons, notating counterpoint, like notating a melody with drone, will often call for a different approach from the standard one. However, unlike a melody and drone, the different melodic lines combined in counterpoint may be of equal interest and importance, so the notation needs to be different from the drone approach as well.

The solution here is to notate the different voices with different types of line that don’t hide each other, in such a way that it will always be clear whether a symbol refers to (for instance) voice A, voice B, or both voices together on the same pitch.

We’ll illustrate this with an excerpt from the Sonata in A Major by César Franck, originally written for violin and piano but often performed with the violin part played one or two octaves lower on the cello. 

The final movement is a “canon”: both instruments play the same melody, but they start at slightly different times, creating the effect that one instrument is imitating the other. The violin plays the melody in a higher register than the piano, so their pitches don’t overlap; but the cello plays it in the same register as the pianist’s left hand (the right hand doubles this an octave higher), resulting in two voices that both overlap and cross.

To notate this, we’ll use a double black line for the piano and a thick grey line for the cello. That way, moments where both voices have the same pitch will appear as a thick grey line with black borders, so neither symbol hides the other. (Only the melodic lines are notated here, without the accompanying harmonies; the octave doubling sign at the beginning (see Wide pitch range), surmounted by the symbol being used for piano sounds, indicates that the piano melody (only) is doubled an octave higher.)

Separation of different instrument lines using differences in the lines themselves.

The same approach can be used for music with more than two voices, provided that no two voices represented with the same type of symbol overlap. Here for instance is a highly space-efficient score of the four-voice round “Frère Jacques.”

The "Frère Jacques" song written in global notation with different voice lines marked with different types of lines, differentiated by colour and fill type.

The lines of the song are numbered at the beginning in the order in which they are sung, with the type of symbol used for each line indicated to avoid ambiguity where two lines (1 and 4) start on the same pitch. The repeat sign indicates that each line is sung twice before going on to the next line. This may not be the easiest score to read, but it contains all the information needed to perform the song.

It must be admitted that this form of notation is quite laborious to draw, even using graphics software. This is one area where Global Notation eagerly awaits a bespoke software program.

In counterpoint, a musical texture is considered as a collection of “voices” each to be read horizontally across the page or screen. But pitch combinations also have a “vertical” dimension that is not always fully expressed just by writing one symbol above another. Our ability to notate pitch combinations is incomplete until we have a way of representing them as something different from the sum of their parts.

Sources of audio

César Franck, Sonata for Violin and Piano in A Major, arranged for cello and piano, fourth movement “Allegretto Poco Mosso,” performed by Mischa Maisky and Martha Argerich, EMI Classical CD, ASIN: B000005GP7, track 4.