I do the Matins on Wednesday night and then continue with the Lauds on Thursday, but I am alone and can change the order. The rest I do as indicated, Friday Matins and Lauds together, and Saturday Matins and Lauds together. If I start on Wednesday, I feel as if I am preparing more reflectively for Holy Thursday.
My first introduction to Tenebrae was in 1980 at Notre Dame. The singing and presentation were spectacular and extremely prayerful. Then, when I lived in England, I attended Tenebrae, as several parishes where I lived held the Wednesday night anticipation. Because I am in the States, I have no idea where Tenebrae could be occurring outside of the Benedictine Monasteries, so I just do it on my own.
If you have the Baronius Press publication of the 1962 Missal, Tenebrae may be found there.
I know Tenebrae is held in England, the Netherlands, Italy, and in other European countries. I have no idea why Americans have not continued the custom. It is supposed to begin two hours before dawn on Thursday in monasteries, or the night before on the Wednesday in parishes. A bare altar with a 15 candelabra fills the sanctuary, and after each Psalm, (and these are all sung), a candle is extinguished, until the church is dark. Sometimes one candle is left lit as the choir processes out with that candle.
When all is dark in the parish version, the people in the pews pick up their song books and bang them on the pew fronts, making the sound of the earthquake when Christ died, or, as some want to state the sound of the Resurrection.
From YouTube, one version. A sublime composition, and the Benedictus is wonderful! One can hear the choir processing out, and I can imagine that happening with the one candle leading them away, leaving all the rest in the congregation in darkness.
My post from 2012