During the holy liturgy in Orthodox churches of Bulgaria, there is one chant ‎that is performed only once a year. Only on Good Friday, the chant ‎‎“Nadgrobnoe ridanie" (Sepulchral lamentation in English), also known as the ‎‎"Opelo Christovo” (Requiem Christ) can be heard in churches here. It is part of a divine liturgy ‎connected with the Crucifixion and is a synthesized "narrative" of the Passions ‎of Christ (the sufferings of Jesus Christ) and the death of Jesus on the cross. ‎

The chant "Nadgrobnoe ridanie" is composed of three parts and has a specific and original melody ‎that has reached us unchanged from time immemorial. On the basis of this ‎anonymous work, one of the masters of the first generation of Bulgarian ‎composers, Dobri Hristov (1875-1941), created a unique polyphonic ‎composition that is still performed in churches today. In this way, the ‎sacrament of the Crucifixion and death on the cross is transmitted as a message ‎to the laity. This sacred moment is very moving and very sad and makes one rethink life. 

Within about 40 minutes, as is the duration of the chant ‎‎"Nadgrobnoe ridanie", the holy liturgy tells us about the pains and sufferings of ‎Christ to become the sacrificial lamb for all people and then to rise again. For ‎this, the songs do not sound so much like a lamentation but rather a praise of Christ's ‎deeds, of the victory over death and as an anticipation of the coming ‎Resurrection.‎

The version of "Nadgrobnoe ridanie" of the Svetoglas male ‎vocal group is shorter than the one performed in ‎church, but it recreates the main message of Good Friday. The music is by Dobri ‎Hristov - the composer who contributed the most to the development of ‎Eastern Orthodox music in Bulgaria. ‎

After studying composition in the class of Antonin Dvorak in Prague, Dobri ‎Hristov worked almost his entire life for the creation and development of ‎choral singing in Bulgaria, notes the prominent choral conductor Prof. Teodora ‎Pavlovich in a review of the Svetoglas album. ‎According to her, it is an exciting fact that the performance of "Nadgrobnoe ‎Ridanie” of the formation was carried out according to the author's ‎manuscripts preserved in the Patriarchal Church of St. Alexander Nevsky in ‎Sofia.‎