The nichavent (νιχαβέντ) element is constructed on the model of the hard diatonic scale starting from the rast [C] position, which serves as its theoretical basis. The name stems from its role as the fundamental element of the Nichavent mode. It is common practice to refer to bouselik (μπουσελίκ) as the transposition on dougkiach [D], as well as any other transpositions. Bouselik finds its counterpart in the Ottoman bûselik element and takes its name from its use of the bouselik position.
In staff notation, a theoretical intervallic structure of 9·4·9·9 commas is defined, classifying nichavent and bouselik as hard diatonic elements. The sub-basis lies 5 commas below the basis and can be reduced to 4 commas because of micro-attraction.
The adaptation of nichavent and bouselik to equal temperament is referred to, respectively, as the equal-tempered nichavent element (or nichavent*) and the equal-tempered bouselik element (or bouselik*) and occurs as shown in the following figure.
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.
