For the text only, but with a translation, click HERE.
For a different way to access the recording above, click HERE.
Note: this office appears to have been quite reworked and also relocated since the publication of the Antiphonale Romanum (1912). See the old version HERE. These same melodies are all still present in the Antiphonale Romanum (1919). Since after this, no other typical edition of the AR was published, the new material must have been promulgated separately at a later date, after which, Solesmes would then be obliged to include it in their edition in the proper location, while removing the old material from the old location. (Hence some of the abnormal page numbers in our 1949 edition of the Antiphonale: it has inserted-page numbers running from 538-1 to 538-16 and then later one very odd page in May numbered “716-724”, all on account of this one feast being changed around.)
If anyone has an edition of this feast’s music which is Typis Polyglottis Vaticanis, that would be of interest (though having approximately zero practical use). Also, if anyone has any insights into the change in the tone of the hymns for this feast, please leave a note. Last I looked, the old mode 7 tone only appears in more recent books such as the Liber Usualis as an alternate melody for O salutaris Hostia, being no longer used in the office.