Sequences were songs that came into the liturgies of solemn feasts and other liturgies (like the Dies Irae, in masses of the dead). They were sung before the gospel until the revision of the Roman Missal in 2002, wherein the General Instruction places it before the Alleluia. Of the many sequences that had been used up until the time of the Council of Trent in the sixteenth century, only four were retained in the Roman Missal of Pius III, and of those, only three were retained in the current Roman Missal, with two (the Easter sequence, Victimae Paschali Laudes and this one) being obligatory, and the sequence for the Solemnity of the Body and Blood of Christ, Lauda Sion Salvatorem, being optional.
I don't know about you, but it's not easy to negotiate music placement in liturgy in these days of resurging subjectivism with practice. As the iron-fisted "by the book" approach to rubrics and liturgy of the latter-day Pope St. John Paul II and his successor Benedict XVI fades away, and the less restrictive, pastoral attitude of Pope Francis suffuses the church, one side effect has been (for me) that it is virtually impossible to use the phrase "the rubrics say" or "we really ought to..." with regard to the liturgy any more. I'm not really complaining about this, it's just that there's no authoritative center of authority in these matters any more other than the desire of the pastor or presider at a particular mass. Since there is pretty general agreement among us on certain basics, for instance, that the readings are from scripture, we follow a general structure, there's a eucharistic prayer, a breaking of bread, and communion, it seems less important whether, for instance, we sing the Gloria every Sunday, use metal vessels on the altar, or sing the two sequences that are "mandatory" in the rubrics on Easter and Pentecost. Sometimes, this works to communal advantage, in my opinion, as when the strictures around "authorized translations" of the psalms aren't observed for singing responsorial psalms or adjusting the obnoxiously non-inclusive language of some of the NABRE readings. But it does call for some compromises and relaxing into "millennium mode" about other rubrics governing music and celebration. By "millennium mode," I mean taking a look at the importance of the disagreement over implementation from the vantage point of a thousand, or, when necessary, ten thousand, years into the future. Is it really going to matter to the future of the church and the reign of God if we don't sing the sequence this Sunday?
As for me, I've set both the Easter sequence and the Pentecost sequence with some success. Obviously, with such a specialized piece of music only used once a year, one has to decide whether the participation of the congregation is of value to the effort. For me it is, though I think for others it need not be. In a parish (or cathedral) situation where time isn't of the essence and a rubrical authenticity is desirable, a choral sung or chanted sequence would certainly be as acceptable as any option. But when I set the Victimae Paschali Laudes for Easter, I used the Latin text and music which are gorgeous in their immediate inaccessibility, but added the familiar Alleluias from O Filii et Filiae as a response by assembly three or four times during the chant, leading into the gospel acclamation using those alleluias.
With the Pentecost sequence, I opted to use the beautiful and really virtuosic translation by Scagnelli, bound to a chant like tune that actually starts on the seventh tone of the natural minor scale, adding another layer of metaphor to the seven-syllable lines of Scagnelli's translation. I named the tune "QUANDO ITA" because the melody bears a certain resemblance to the Bill Withers tune "Ain't No Sunshine When She's Gone." (QUANDO ITA is an approximate Latin translation of "when she's gone.") There's no symbolism (nor plagiarism) in the resemblance to the bluesy Withers anthem, it's just a motif that is easily singable, woven into a melody with inner repetition to make it memorable.
That's it for today, just wanted to get another song into the "Songstories" list that connects to the rhythm of the liturgical year. In case you're wondering, at St. Anne we will be singing the sequence as a "call to worship" before mass, rather than before the Alleluia. I'm trying to choose my "battles" these days, looking for some balance in my life, saving my energy for what, I hope, is more important than a song, however ancient and beautiful.