From Youtube: Beneventan Chant

Beneventan chant is a liturgical plainchant repertory of the Catholic Church, used primarily in the orbit of the southern Italian ecclesiastical centers of Benevento and Montecassino, distinct from Gregorian chant and related to Ambrosian chant. It was officially supplanted by Gregorian chant in the 11th century, although a few chants of local interest remained in use.

Here is a sample of Beneventan Chant from Youtube: Otin to Stauron - O Quando in Cruce, sung by Ensemble Organum in Greek and Latin, from their album, Chants de la Cathédrale de Benevento: Semaine Sainte & Pâque.

What is interesting is that three bilingual (Greek and Latin) antiphons, of this is but one, were sung in Benevento and some other Italian centres as part of the Adoration of the Cross service in Holy Week. Some of these chants seem to have Eastern origins: this particular sample for instance, found in sources from places such as Benevento and Ravenna, is actually a version of a Byzantine troparion which can be followed back to the rite of Jerusalem in the 7th century. Its presence in Ravenna should mean that it was already used in the liturgy there before the fall of the Exarchate of Ravenna to the Lombards in 752.

Received Greek Text
(Sung during the Ninth Royal Hour of Holy Friday in the Byzantine liturgy)

Ὅτε σὲ Σταυρῶ προσήλωσαν παράνομοι, τὸν Κύριον τῆς δόξης, ἐβόας πρὸς αὐτούς.
Τὶ ὑμᾶς ἐλύπησα; ἢ ἐν τίνι παρώργισα;
πρὸ ἐμοῦ, τὶς ὑμᾶς ἐρρύσατο ἐκ θλίψεως;
καὶ νύν, τίμοι ἀνταποδίδοτε; πονηρὰ ἀντὶ ἀγαθῶν,
ἀντὶ στύλου πυρὸς Σταυρῶ μὲ προσηλώσατε,
ἀντὶ νεφέλης, τάφον μοὶ ὠρύξατε,
ἀντὶ τοῦ μάννα, χολὴν μοὶ προσηνέγκατε,
ἀντὶ τοῦ ὕδατος, ὄξος μὲ ἐποτίσατε.
Λοιπὸν καλῶ τὰ ἔθνη, κακείνά με δοξάσουσι,
σὺν Πατρὶ καὶ ἁγίω Πνεύματι.

Transliterated Greek text
(text based on MS. 1343 (Sessorianus 62), Rome, Biblioteca Nazionale, folio 80v)

[O]te to stauron proschiloson paranomi kyriontis dosis evoa pros autus
timas elipsas gem tini parorgersas pro emutis ymas elisato e gliesos
che non ti mi antappoditote pomiram anti agaton
anti stilu piros stauro me proschilosate
anti tu manna olimin pro sinegate
ante tu idatos oxos meos potisate
lipon chalo ta etni chachinna me doxa susi si
sin patri che agyon peunemati.

Latin

O quando in Cruce confixerant iniqui Dominum glorie, ait ad eos:
Quid vobis molestus sum, aut in quo iratus sum?
Ante [/ Absque] me, quis vos liberavit ex angustiis?
Et nunc quid michi redditis mala pro bonis?
Pro columna ignis in cruce me configitis:
Pro nube sepulchrum michi foditis:
Pro manna fel me potasti:
Propter aquas aceto michi in poculum porrigitis:
Ego vocabo gentes, ut ipse me glorificent,
una cum Patre et cum Sancto Spiritu, Amen.

English

When transgressors nailed to the Cross the Lord of Glory, He said to them:
"How have I troubled you? Or in what have I angered you?
Before [/ Besides] me, who has delivered you from distress?
And have you not given me back evil for good?
For the pillar of fire you nail me to a cross,
For the cloud you dig me a tomb,
For the manna you made me drink gall,
For the water you offer me vinegar to drink.
I shall call the nations, that they may glorify me,
together with the Father and with the Holy Spirit," Amen.

Another version: