Chant
There are eight tones. Most of the liturgies of the church are chanted using these tones.
Each tone has a special melody. The melody used to chant different parts of the liturgy are indicated by the tone number.
Resurrectional Troparia apply specific lyrics to particular tones. Each week, the resurrectional tone is sung at a designated place in the Divine Liturgy.
As such, Orthodox often learn the melody of the tones while singing along with the cantor. But, the weekly tone might also be used when reciting daily prayer at home (or at other Orthodox gatherings).
In fact, the same melody applies every time a tone is used (Well, it’s complicated: There are also a set of tones for Vespers and other special melodies).
The unique chanting sound heard when Orthodox Chrisitians gather is due, in part, to the fact that these tones are skillfully applied to texts even when such text doesn’t “fit” with the melody!
BTW: Our tradition is Carpatho-Rus (regarding the church home — a region of the Carpathian Mts. in Eastern Europe — and NOT specific to the language [we use English] OR to the nationality of our members [varied]). Our chant style is plainchant. Other traditions and styles use different melodies.
Freely Ye Have Received Freely Give