Our service books are full of paragraphs headed by a Greek or Russian
word & the number of a tone. This means that this hymn is intended
to be sung
in
the indicated tone. There are basically four categories of tone for
use:
Prokeimenon,
Troparion,
Irmos(sometimes spelled Heirmos or Eirmos),
&
Stichera AKA samoglas AKA idiomelon.
Most of the movable parts of the
services should be sung with
the pertinent melody. For paragraphs whose title is one of these four
names
the choice is obvious.
If it is called:
Troparion, Kontakion, "God is the Lord", or
Hypakoe,
then you use the
Troparion melody .
If it is called:
Photogogicon, "Hymn of Light" or Exapostilarion, then you use the
Troparion melody (if no tone number is indicated then either read it or
sing
it in tropar
tone 3).
If it is a weekday during a fast & it says to sing alleluia, you
sing alleluia three times with the prokim melody
Everything
else can be sung with the Stichera melody. There are always exceptions,
the most prominent is that the troparia of canons should be read &
not sung.(except at Pascha when they are sung with the irmos melody)
Below is a handy lookup chart to bring up relevant model melody as
sung
at St. Sava. On the top is the tone number. On the left is the
category
of tune
On this page
there is a very helpful glossary explaining this terminology.
