The previous articles in this series discussed the texts and melodies of the Mass Propers. This article concerns the technical elements of the melodies, which are wrapped up in a concept called modality.

N.B.: in the process of writing this article, the author came across a detailed article on a similar topic, written by Angela Rocchio of the International Chant Academy. Interested readers may consult her article on The Moods of the 8 Church Modes for a somewhat differently-focused, yet still worthwhile, discussion of this subject.

A Brief History of the Modal System

A full history of how ancient music theory developed into the modal system used by the Western church is far beyond the scope of this essay. The interested reader may find in-depth summaries in these and similar articles: Mode (music), Musical system of ancient Greece, and Hagiopolitan Octoechos. For the present context it will suffice to say that the modal system has its theoretical roots in the music of ancient Greece, but only the concepts remain: collections of notes grouped in scales with Greek-sounding names, exhibiting particular aesthetic or emotive characteristics.

Historically speaking, the chants predate this modal system. Modal classification is a theoretical construct that was invented to describe the tonal structure of the chants. This is the case throughout musical history: the codification of the theory that describes the music (sonata form, for example) postdates the composition of the music (in this case, the 18th-century instrumental sonata). The theory is written to describe what is going on in a pre-existent corpus of music.

It should be noted that non-Gregorian Western chant traditions (such as Mozarabic or Ambrosian chant) and the Eastern chant traditions do not operate according to this system. Though they have their own system of modes and even share some of the nomenclature with the Gregorian system, and though it is possible that they cross-pollinated in antiquity, they are quite different—and in the case of the Eastern traditions, radically so.

As part of this work, the chants were each classified according to one of the eight modes.
The eight modes were codified by the end of the eighth century, and so by that point every chant had a mode assigned to it.

Modal Character

Writers over the centuries have applied various emotive characters to each mode. This seems to have begun with Plato, who wrote the following in The Republic in his discussion of the music that would be allowed in his ideal society:

As we banished strains of lamentation, so we may now banish the mixed Lydian harmonies, which are the harmonies of lamentation; and as our citizens are to be temperate, we may also banish convivial harmonies, such as the Ionian and pure Lydian. Two remain—the Dorian and Phrygian, the first for war, the second for peace; the one expressive of courage, the other of obedience or instruction or religious feeling.

Plato here identifies certain modes with specific emotive characters: the Mixolydian mode is associated with lamentation; the Ionian and Lydian with conviviality; the Dorian with war and courage; and the Phrygian with peace and obedience. (N.B.: the modes to which Plato refers are not the same as the eight church modes, even though they bear some of the same names; thus, the reader should not try to apply Plato’s correlations to the church modes.)

Since Plato’s time, this general concept has been applied by countless theorists, in a number of specific ways, none of which necessarily agree with each other. The following list of modal characters is quoted by Pierre-Nicolas Poisson in his Nouvelle méthode pour apprendre le plain-chant (1789). This list supposedly goes back all the way to Guido of Arezzo (ca. 991–after 1033), who is credited with the invention of the musical staff. While the list is not “authoritative” any more than any other list can be, it is at least old. Furthermore, in my opinion these characters match rather well with the characters of the associated modes/Psalm tones, and thus the list “checks out,” even if the terms are vague (for example, what does “perfect” mean in the context of a melodic character?):

Number	Name	Character
I	Dorian	Gravis (serious)
II	Hypodorian	Tristis (mournful)
III	Phrygian	Mysticus (mystical)
IV	Hypophrygian	Harmonicus (harmonious)
V	Lydian	Laetus (joyful)
VI	Hypolydian	Devotus (devotional)
VII	Mixolydian	Angelicus (angelic)
VIII	Hypomixolydian	Perfectus (perfect)

Though Plato was likely the first to write down the concept of modal character, there is a scriptural parallel: In 1 Samuel 16:14–23, David is able to manipulate Saul’s emotions by playing his harp in various ways.

A Technical Description of the Modes

The concept of modes/modality can be confusing. Perhaps the easiest way to describe a mode is to say that it is a tonal universe. Traditional Western music composed since the eighteenth century (the so-called “common practice period”) operates in two of these universes: major and minor. But in earlier Western music extending back through the Middle Ages, there were more tonal universes: eight to be precise, known as the eight church modes. The most straightforward way of describing a mode is through its scale, which is simply the notes contained in the mode, arranged in series from lowest to highest. The notes in the scale are called the gamut. Though each mode has a Greek name, in liturgical use the modes are referred to by number. Each mode has a corresponding Psalm tone associated with it, which will be discussed shortly. The tones and modes are numbered in the same way: e.g., Tone IV is the Psalm tone associated with Mode IV.

N.B.: Depending on who you ask, there are actually as many as twelve modes. Certain Lutheran resources (such as Franz Eler’s Cantica sacra (Hamburg, 1588)) even catalogued the chants therein according to a twelve-mode system. However, this was something of a fringe practice. Because it is the eight-mode system that held sway throughout the Middle Ages, we will consider only the traditional eight-mode system here, without increasing the complexity of the already complicated issues at hand by introducing the subsequent four modes.

Final, Range, and Dominant

Warning: the following two paragraphs comprise a highly technical discussion of modal characteristics. These details are elucidated in the subsequent diagram, which ought to clear things up.

Chant melodies are classified into modes according to their final and range. The final is the last (final) note of the melody. Melodies with a final of D are in Modes I or II; melodies with a final of E are in Modes III or IV; melodies with a final of F are in Modes V or VI; and melodies with a final of G are in Modes VII or VIII. The range (or ambitus) refers to where in the mode the final sits. In authentic modes the range extends about an octave above the final, whereas in plagal modes the range is the same size but extends both above and below the final. (Another way of describing this is to say that the final is at the bottom of the range in authentic modes, but in the middle of the range in plagal modes.) The odd-numbered modes are authentic, and the even-numbered modes are plagal. Thus, a chant that ends on E and has a range that generally stretches evenly below and above that E (roughly from A to A, by perhaps a note more in either direction) is in Mode IV. For the sake of comparison, our modern major/minor tonal universes correspond closely, though not exactly, to Modes V or VI (major) and I (minor).

Each mode has a specific dominant (sometimes referred to as the tenor or tuba). This is the note around which the melody gravitates as it progresses (this is similar to the concept of tonal centricity in twentieth-century music). The dominant of each mode is also the reciting tone in the corresponding Psalm tone. In authentic modes, the dominant is a fifth above the final; in plagal modes, the dominant is a third below the corresponding authentic dominant. The exception to this rule is that if a final falls on the note B, it is raised to C—thus the dominants in Modes III, IV, and VIII are something other than a fifth above the final. (N.B.: The reason for B being disallowed has to do with a combination of acoustics, semantics, music history and theory, and convention, and is unnecessary to explain fully in this context. Nevertheless, the note B has unique properties because of its location relative to the other notes, and when it is combined in certain ways melodically and/or harmonically with other notes there are ramifications to be dealt with. In chant and polyphony through the early 17th century it is frequently—though not always—flattened or raised so as to avoid it, and this convention is sometimes assumed and not always notated. The interested reader may consult this article on the hexachord in the Middle Ages for further information.)

All of the above is laid out in the diagram below:

Note that this scheme of range, final, and dominant described above does not take into account transposition. For example, the Communion Passer invenit for Oculi is in Mode I, but it is notated a fifth higher, ending on A. This is to allow for a B-flat to appear that otherwise would be outside the gamut (this is one of the ramifications hinted at above in the discussion about the note B). Such transposition for notational reasons is relatively rare, and for over 95% of the chants one may encounter, classification via final and range is straightforward. When modal classification is less clear, however, we must resort to what might be described as “calling cards.”

Modal Calling Cards

As a tonal universe, each mode has specific melodic turns of phrase that act as “calling cards.” Sometimes these calling cards are restricted only to specific genres. The incipit (first several notes) to Mode I Introits is one such calling card:

This figure doesn’t open every Mode I Introit, but it opens many of them, three of which are given above). It would sound completely out of place in, say, Mode VIII. Here is another figure, which is extremely common in the Mode V Gradual verses:

Here is a cadential figure that appears in the Introits in Modes I and VIII (where it is altered by the German dialect to avoid the note B):

This same figure appears in Mode V and VI Introits, but in a longer way that is unique to these modes:

Here is a melodic figure that is common to the Tracts (a genre exclusive to Modes II and VIII):

The modes predate written music, and so their calling cards, in an aural way, are the primary way they were conceived. Prior to being written down, the corpus of chant was transmitted orally. This seems impossible for our modern minds to imagine. Yet the medieval mind operated differently than ours, and the modes are structured to take advantage of that. If one is intimately familiar with the mode in question, one would be able to remember and reconstruct a melody in that mode via the mode’s calling cards.

As polyphony developed, each mode gained specific harmonic characteristics, expressed in the harmonic progressions a composer or organist would use. The harmonic specifics of each mode are beyond the scope of this article; however a few examples will suffice to provide a general idea. Mode I, for example, ends with a D major sonority, and along the way touches on the keys of A major and F major. Mode II appears almost invariably in polyphony as what we would call G minor. Modes III and IV are identical in polyphony, excepting for their final chord: Mode III ends on an A-major sonority (or sometimes G major), and Mode IV ends on an E-major sonority. In fact, it is possible for the same organ intonation to introduce a chant in either Mode III or IV, by changing only the final chord. Here is a brief example that would be in Mode IV if the player were to stop after the fourth measure, but is in Mode III because of the final measure:

The Psalm Tones

Each mode has a Psalm tone that goes with it—or more precisely, that sits within the mode. It is the tradition of the Church to sing the Psalms to any of these eight so-called Gregorian Psalm tones (with a ninth used only for Psalm 114 (In exitu Israel) and sometimes the Magnificat), which are of ancient origin. Some scholars claim that the Gregorian Psalm tones preserve vestiges of the music used in pre-Christian Jewish worship. Though this is impossible to verify, it is not unlikely.

Anatomy of a Psalm Tone

When we think of Psalm tones, we generally think of a (perhaps boring) formula of notes, and that is not incorrect. But there is much more going on in the historic Gregorian Psalm tones. Properly speaking, a Psalm tone consists of an incipit, a reciting tone, a flex, a medial cadence, and a terminal cadence. Tone II will serve as an example:

Note that the reciting tone appears in both halves of the Psalm tone: before and after the medial cadence. The flex appears only in the first half of the tone, and is only used when it is needed. It is always either a tone or a minor third below the reciting tone, depending on the mode. The parenthesized notes are used only as needed to account for the varying numbers of syllables. The flex and parenthesized notes will be discussed below under the section concerning pointing.

In the German dialect used in the Lutheran chant books of the 17th century, there is also a medial incipit. Here is Tone II as given in Eler’s Cantica sacra. The medial incipit is on the words “in Deo:”

As far as the author is aware, the medial incipit only appears in the German dialect. Modern musicians are liable to encounter them chiefly in the Lutheran organ and choral music incorporating the Psalm tones (e.g. the hymn and Magnificat versetti by Heinrich Scheidemann, Jakob Praetorius, Samuel Scheidt, and the like). This makes the medial incipit rather a niche issue, and so the resources for the more mainstream chant traditions (such as the modern Roman tradition standardized at Solesmes) do not mention it.

The ninth tone mentioned above in passing is unique among the Psalm tones in two ways. Firstly, it has no corresponding mode (though it is closest to Mode I). Secondly, the reciting tone differs between the first and second halves of the tone: in the first half the reciting tone is A, but in the second half it is G. Because the reciting tone moves, Tone IX has a special title: it is the Tonus peregrinus, the “wandering tone.” As mentioned above, it is used only for Psalm 114 and the Magnificat—in fact, it is the basis for the German Lutheran chorale version of the Magnificat, Meine Seele erhebt den Herren. Here is this chorale as given in Johann Hermann Schein’s Cantional of 1645:

And here is the same thing put into modern notation, which makes it easier to see the fact that it is a Psalm tone:

There are both solemn and ferial versions of each Psalm tone—the solemn tones are more elaborate with more notes in their incipia and cadences, and are used for the Magnificat on feast days. There are also slightly differing versions of the tones that are used for the Introit and Communion verses.

Here are the nine Psalm tones in their ferial forms as given in the Liber Usualis. This source is unreliable from an historic standpoint, but which is useful on account of its systematic organization. Therefore, though these forms of the Psalm tones do not accord precisely with the German dialect, their unique melodic characteristics are still visible. Note that each Psalm tone takes the dominant (reciting tone) and final from its mode:

Here are the eight Psalm tones in their solemn forms (Tone IX lacks a solemn form). The second half of the tone is identical to that in the ferial form, but the incipia and medial cadences have additional notes. The flex is not given here, but it would be included if necessary:

Accents and Pointing

Each Psalm tone has either one or two accents in each half of the tone (dubbed medial accents and terminal accents). Each accent may have up to three preparatory syllables leading to it. The accents are simply notes upon which accented syllables in the text are to fall. To apply the text to the tone, one simply divides the text in half at a sensible point, placing the last one or two accented syllables in each half of the tone on the accents. The remaining syllables fall into place, with the parenthesized notes used as needed. The accented notes are marked in the Psalm tones above with a tick.

Because the texts are applied to the Psalm tones via lining up the accents in the text with those of the tone, it is possible to sing any Psalm to any Psalm tone without the aid of any textual aid whatsoever. To do this requires that the persons involved are familiar with the rules, with the location of the accents and the number of preparatory syllables in each tone, and with the accents in the text. Since this is not the case in the vast majority of situations, extra symbols need to be added to the text in order to indicate how the text is to be sung to the tone. The term pointing refers to the act of adding characters to a text in order to allow it to be sung to a melodic formula. This also means that the text does not have to be set within the music—it can appear as a block of text.

Here are two examples of the same Latin Psalm text (Psalm 110:1–2), first pointed to the straightforward Tone V (one medial accent, two terminal accents), and then to the more complex Tone IV (one medial accent with two preparatory syllables, one terminal accent with three preparatory syllables):

With Latin texts, this process is infallible and will never produce an error (i.e., an accented syllable on an unaccented note or vice versa), because in Latin there are no accented final syllables. English, however, has accented final syllables, and so this process does not always work. Liturgical musicians have come up with a few ways to solve this problem, such as slurring together the final terminal accent and the following notes on the same syllable. The author’s preferred solution is to follow the same process as for Latin, but to allow an accented final syllable to fall on the last (unaccented) note of a tone if necessary. This has the advantage of allowing the textual accents to otherwise line up with the accents in the tone; it also avoids altering the structure of the Psalm tone. See for example Psalm 110:5, set to Tone V:

Throughout history, myriad systems have been used to point text. The idea goes all the way back to Hebrew diacritics, which indicate not only vowels but also cantillation, the melody to which the text is to be sung. The following system is what is used in the Liber Usualis, which the author prefers not because of its source, but because it is minimalist and textually based: it does not add superfluous symbols to the text but relies chiefly on the accents intrinsic to the text (albeit printed on the page).

• The asterisk (*) indicates the halfway point of the chant. This is also sometimes indicated via a colon (:).
• The cross (†), if it is present, indicates the flex, which applies to the preceding syllable(s). The final accented syllable before the flex is sung on the reciting tone, and the subsequent weak syllable(s) is(are) sung to the lower note. Because of Latin word stress, there are never more than two weak syllables after an accented syllable—thus, there are never more than two flexed syllables.
• The accents in the text are noted with acute accents (´) above the vowel in the accented syllable.

This system may be viewed as it appears in the Liber Usualis in the image of Psalm 111 below, under the heading Differentiae. With only these elements, the text can be sung to any Psalm tone. As long as the singer knows where the accents fall in the tone he is using, no other alterations to the text are necessary. But because each tone is slightly different in number of accents and preparatory syllables, the Liber Usualis pointing provides two additional ease-of-use features:

• The accented syllables that correspond to the medial and terminal accents in the Psalm tone are bolded.
• The preparatory syllables are italicized.

These features skew the pointing to whatever specific Psalm tone is intended.

Differentiae

Except for Tones II, V, and VI, each tone has between two and ten differing terminal cadences (differentiae), which vary depending on the starting note of the antiphon. See the following image from the Liber Usualis, which exhaustively catalogues all the differentiae for Tone I:

The differentiae are rarely pointed, because they almost always apply only to the final syllable—there is usually no need for pointing. If there is a need to point them, it appears in a parenthetical note in the text. See for example this excerpt from Confitebor tibi, Psalm 111:

Admittedly, all this has been very confusing to read, but it is much easier to absorb by example than it sounds here. It is even easier than that to absorb by osmosis: that is, by embedding oneself into a community that prays the daily Offices, with its many Psalms sung to the Gregorian Psalm tones with matching antiphons. Not coincidentally, this is how these things were learned for centuries before they were written down in textbooks and the like. For the time being, the above examples will have to suffice.

Thus far we have examined the general characteristics of the texts and melodies as well as the modal system associated with the Propers as received by the Church of the Augsburg Confession. Before we examine in detail the individual Propers by genre, there is one more general element to which we must turn. That is the division of labor: who sings what and when, which will be the subject of the next article.