The Elements of the Greek Modal System: Trichords, Tetrachords, and Pentachords

This excerpt is from my book The Theory of Rebetiko, where I delve into the modal system of Greek music as it relates to the rebetiko genre. To access the complete text—including detailed discussions, tables, illustrations, and musical transcriptions of the examples—visit this page and explore the rich world of Greek modal music.

The Elements

The Greek modal system can be explained using elements. An element is defined as a sequence of three, four, or five consecutive notes arranged in a specific intervallic structure. Each note within the sequence is called a degree. Depending on the number of degrees, elements are categorized as follows:

• a trichord (3x) consists of three degrees;
• a tetrachord (4x) consists of four degrees;
• and a pentachord (5x) consists of five degrees (see the following figure).

Some elements appear exclusively as a trichord (e.g., moustear), a tetrachord (e.g., ousak), or a pentachord (e.g., nikriz). Other elements may appear both as a tetrachord and a pentachord (e.g., rast), or even in all three types (e.g., segkiach).

Numbering the Degrees

The numbering of an element’s degrees proceeds in ascending order from the lowest note. A trichord is composed of the I, II, and III degrees; a tetrachord is composed of the I, II, III, and IV degrees; and a pentachord is composed of the I, II, III, IV, and V degrees (see the following figure).

Naming the Degrees

Each degree of an element is named according to its position within the sequence of notes. The I degree is referred to as the basis and is represented on the staff with an open notehead, unlike the other degrees, which are represented with a filled notehead. The last degree is referred to as the peak, while the degrees between the basis and the peak are referred to as the intermediate degrees. In addition, there is the sub-basis, which precedes the basis and is represented by a smaller notehead (see the following figure).

Melodic Attraction

The melodic attraction (briefly: attraction; symbol: “–>”) is a phenomenon that temporarily modify the pitch of one or more degrees of an element (and also of a mode, as we will later discuss). The attraction is determined by two characteristics of musical phrases:

• order, i.e., the direction of the phrase, which can be either ascending or descending;
• and gravitation, i.e., the tendency of phrases to gravitate, to revolve around a note considered melodically significant; this note can attract—that is, draw closer—an adjacent degree by altering its pitch.

Attraction can be either ascending or descending. Ascending attraction may occur in ascending phrases and/or in phrases gravitating around the adjacent higher degree. Descending attraction may occur in descending phrases and/or in phrases gravitating around the adjacent lower degree.

Attraction in the strict sense change the pitch of a note by at least 4 commas (e.g., D –> D#; B 1 comma flat –> Bb) and must be explicitly indicated on the staff. In contrast, melodic micro-attraction (briefly: micro-attraction) change the pitch by only 1 or 2 commas (e.g., E 1 comma flat –> E; B 1 comma flat –> B; F# –> F 5 commas sharp). Like attraction, micro-attraction can be either ascending or descending; however, it does not need to be explicitly indicated on the staff, as its execution is often optional or implicitly understood within performance practice.

Classification of the Elements

Each element is defined by two qualities that determine its intervallic structure: its genus and its character. The genus classifies an element as follows:

• diatonic, when the element is composed exclusively of intervals no larger than a Pythagorean tone (i.e., 4, 5, 8, or 9 commas);
• or chromatic, when the element contains at least one interval larger than a Pythagorean tone (i.e., between 10 and 13 commas).

The genus of an element can have two different characters: hard or soft. The character of a diatonic genus element is classified as follows:

• hard, if the element consists only of intervals of limma (4 commas) and Pythagorean tone (9 commas);
• or soft, if the element contains intervals of Pythagorean tone (9 commas) and at least one interval of apotome (5 commas) and/or Didymus’ tone (8 commas).

The character of a chromatic genus element is classified as follows: hard, if the element includes intervals of 12 or 13 commas, among others; or soft, if the element includes intervals of 10 or 11 commas, among others. In fact, staff notation makes no distinction between the hard and soft character of chromatic elements (see the description of the chromatic elements). While the theoretical intervallic realization of these elements is determined by their occurrence within specific modes, in practical application, their interpretation is generally left to the musician’s discretion and artistic preference.

Names of the Elements

The names of the elements commonly used in the Greek modal system are largely derived from the names of corresponding elements or modes in Ottoman classical music theory. In most cases, these names hold no meaning in the Turkish language, as they originate from Persian or Arabic. Some names are nouns (e.g., hisâr, «fortress»; uşşâk, «lovers») or adjectives (e.g., hümâyûn, «regal»; rast, «correct»). Others reference place names (e.g., nihâvend, «from Nahavand»; nişâbûr, «from Nishapur»), populations (e.g., acem, «Persian»; kürdî, «Kurdish»), or musical terminology (e.g., yegâh, «first position»; dügâh, «second position»; segâh, «third position»; çârgâh, «fourth position»; pençgâh, «fifth position»).

While the names used in the Greek and Ottoman modal systems are essentially the same, it is crucial to avoid oversimplifying or conflating the identification of elements, and particularly the modes, in these two musical traditions. Although they appear similar at first glance, they are fundamentally distinct. To reinforce this distinction, I opted to use Greek terminology instead of Ottoman (e.g., tsargkiach instead of çârgâh, kiourdi instead of kürdî, etc.)—which would not require transliteration into Latin characters. Element names should be written in lowercase to distinguish them from the often homonymous names of modes, which are always capitalized (e.g., rast, the element; Rast, the mode).

Hard Diatonic Elements

The hard diatonic elements are initially constructed as tetrachords on the model of the hard diatonic scale and include nichavent, kiourdi, and tsargkiach. These elements are composed solely of Pythagorean tones (9 commas) and limma} (4 commas).

Soft Diatonic Elements, and Their Derivatives

The primary soft diatonic elements are initially constructed as tetrachords on the model of the soft diatonic scale (see figure vref{derivazione-elementi-dolci}) and include rast, dougkiach, and segkiach (the mono-flat in parentheses on dik chisar is further explained in section vref{la-microbemolle}). These elements are composed of Pythagorean tones (9 commas) and at least one apotome (5 commas) or a Didymus’ tone (8 commas).

In addition to these elements, there are four others that result from the alteration of a degree: sazkiar and petzgkiach, both derived from rast; saba, derived from dougkiach; and moustear, derived from segkiach (see figure vref{elementi-dolci}).

Chromatic and Reentrant Elements, and Their Derivatives

The chromatic elements consist of at least one interval ranging from 10 to 13 commas (see figures vref{elementi-cromatici}) and include chitzaz and nikriz. In addition to these elements, there are pireotiko, derived from chitzaz, as well as chisar and choumagioun, two so-called reentrant elements.

The Elements of the Greek Modal System