Christ is risen
The troparion of Pasha is sung many times throughout the services of the Paschal season; most likely it is for that reason that the prostopinije tradition provides a number of different settings.
Any of the following may be used when “Christ is risen” is appointed to be sung:
Christ is risen (tone 5 special melody) - this is the most commonly sung version, used "officially" during the liturgical services
Christ is risen (A) - another melody
Christ is risen (B) - another melody, also called the "march"
Special melodies are also used when “Christ is risen” is sung at the dismissal of the services, or as a festive conclusion: