In the Orthodox Church every Sunday we celebrate the Resurrection of Christ with a series of hymns in a particular mode (or tone) of Byzantine music. There are eight modes in Byzantine music and each Sunday is dedicated to one of them, with the cycle of the eight modes, known as the Paschal Cycle, restarting again every eight weeks. The texts for these Services are contained in the Parakletiki.
During Bright Week, one mode (with the exception of the Seventh Mode — known as the "Grave Mode") is assigned to each day:
Sunday of Pascha (Mode One)
Bright Monday (Mode Two)
Bright Tuesday (Mode Three)
Bright Wednesday (Mode Four)
Bright Thursday (Mode Five)
Bright Friday (Mode Six)
Bright Saturday (Mode Eight)
Bright Week is considered to be one single joyful day, although the celebrations on the Sunday of Pascha are the most solemn. The Divine Services are completely different during this time than any other time of the year. Everything during the service is sung joyfully, rather than read. There is no reading from the Psalter, and the services are much shorter than usual.
In the Parakletiki, at the end of each mode there are verses of praise for each particular mode and the role it plays in praising the Resurrection of Christ. Below are translations of these verses as translated by anastasis.org.uk.
The art of music marvels at your sounds,
Gives you the first place. Ah, how well deserved!
As you are called First Mode by music’s art,
First then be eulogised by us in words.
O First, the first of beauties you obtain;
First prize you hold of all in every place.
Though only second place in rank you hold,
First pleasure falls to you of honeyed flow.
Your melody, all honeyed and most sweet,
Cherishes bones and gives to hearts delight.
The Sirens surely sang in second Mode,
So gently flows your song with honeyed drops.
Though third, yet to express brave manly toils,
Close neighbour of the first are you, O Third.
Plain, simple, wholly masculine, O Third,
You are, and so we honour you, O Third.
Source of a multitude of equal count, O Third,
You to a well-tuned multitude belong.
A festal and a dancing tone, you bear
By musical opinion a fourth boast.
Dancers you welcome, and you form them too,
To voices give the prize, on cymbals beat.
You, the fourth Mode, as filled with melodies,
The serried lines of dancers eulogize.
PLAGAL OF THE FIRST MODE
Mournful you are and greatly pitying,
But for the most part rhythmically you dance.
O mind, which art with music has informed,
Which is the bent oblique of plagal tones?
Rank holds you fifth, but first of the unique,
And calls you so, O Plagal of the First.
PLAGAL OF THE SECOND MODE
Sixth Mode in order, but by far the first,
You rank as second in the second group.
Double-compounded the delights you bear,
Though only second in the second rank.
O dulcet-moded cicada, honey-sweet,
Can any then not love you, fair Mode six?
For regiments of hoplites a fit tune,
You take and bear the appellation grave.
One who hates thoughts to be expressed with shouts
Loves the plain tone that bears the title grave.
With manly song you murmur, second-third;
Though many-sided you have simple friends.
PLAGAL OF THE FOURTH MODE
Seal of the modes, O Plagal of the Fourth,
As bearing in yourself all fairest sounds.
You broaden out the ranges of the songs,
The final flourish of the Modes, and end.
As limit in both notes and voices’ pitch,
Limit of sound I call you twice, and end.