Liber Responsorialis pro Festis I Classis et communi Sanctorum iuxta ritum monasticum Adnectuntur Invitatorium et Hymnus Aliorum Festorum, Solesmes, 1895
Where to find it
The good news is that the Liber Responsorialis (with 1924 supplement) can be downloaded for free from the CC Watershed library: Liber Responsorialis (194 MB).
What it contains
The book provides the chant for invitatory, hymn, antiphons (and listing the psalms they are attached to) and at least some of the responsories for a selection of major feasts and seasons.
It also contains some of the 'ordinary' chants, such as the chant tones for Psalm 94.
The book can be frustrating in its gaps though.
The proper of time section, for example, contains the complete chants for Christmas and the Epiphany, for example, but then bypasses Lent altogether, skipping straight to Easter. The separate 'responsories of time' section contains some of the responsories for Sundays of the year, but typically only one or two (out of twelve).
The list of feasts it covers is quite small and eclectic.
What it doesn't contain
The chants are for major feasts including some Sunday responsories - but it doesn't contain the weekday hymns and texts used throughout the year. There are also quite a few responsories for Sundays of the year missing.
The Brignoles Nocturnale project is slowly working fill in these gaps, but in the interim, you can find some of the responsories on the Nocturnale Romanum Project website, and supplement it with this book where possible.
