I thought it might be helpful to bring together a list of the posts from a previous series on the Office of the Dead, as well as relevant notes I've posted since. I'll also post a few notes to fill in the remaining gaps.
On saying the Office of the Dead
Saying the Office of the Dead for the souls in purgatory is one of those good works that all Catholics can undertake.
In the middle ages it became extremely popular, and it was a standard to arrange to have the 'placebo et dirige' (the opening words of Vespers and Matins respectively) said for the deceased on the day of their funeral, as well as on subsequent anniversaries.
The Office of the Dead is a votive Office that can be said on any day for a particular person who has died. In accordance with a Bull of Pope St Pius V, monasteries used to say it for the souls in purgatory on a available ferial day of the month, as well as on Mondays in Advent and Lent.
Its origins are unclear - there certainly were prayers that formed a Mass and Office for the Dead in the earliest years of Christianity, however the version of this Office we use today probably dates from the seventh century. Its form is identical in the traditional forms of the Benedictine and Roman breviary, and it consists of I Vespers, Matins (of one or three nocturns) and Lauds.
Links to notes on the psalms of the office can be found below.
Psalm 114 (and in context of Monday Vespers)
Psalm 129 (and in the context of Tuesday Vespers)
Nocturn I (Sunday, Monday and Thursday)
Introduction to Psalm 7
Nocturn II (Tuesday and Friday)
Nocturn III (Wednesday and Saturday)
Psalm 39 in the context of Tenebrae
Introduction to Psalm 40
Introduction to Psalm 41 (St Bellamine's commentary on Ps 41)
Introduction to Psalm 64
Canticle: Isaiah 38 & here