Here is one of the texts for the Solemnity – about halfway down, the words ‘Tu es Petrus’ can just be made out. The manuscript shows a form of chant notation which predates the four-line stave, indicating merely the structure and direction of the melody. It is still used today to determine accuracy of interpretation as a kind of musical ‘exegesis’ of the text.
Peter and Paul are elsewhere described as ‘twin olive branches’, as in this sixth century Latin hymn: ‘Twin olive branches, pouring oil of gladness forth, Your prayers shall aid us, that for all our earthly worth, Believing, hoping, loving, we for whom ye plead, This body dying, may attain to life indeed’.
May these great saints pray for us, in all our present needs, and may God bless you this day.