1.22 — O mi custos

NotazioneDatazionesec. XI; ?
NoteNotation was added to the first eleven lines and lines l-li. The ink colour and range of signs are similar to the notation added to strophes two to five of Qui signati in the same manuscript; indeed, the two notations may be the work of the same scribe. The letter notation uses the common two octave 'a' to 'p' system, but the 'b flat' in the middle of the system is represented by the letter 'b' rather than by the usual slanting 'i'.
TrascrizioneTrascrizioni
diplomatiche		 Omicustos-Paris1928-1
Trascrizione
alfanumerica		2b, 1a, 1a, 1c, 1a, 1c, 1a, 2a, 1a, 1b, 1a, 1a, 1a, 1b, 1c | 1c, 1b, 1a, 1a, 1a, 1b, 2a, 1b, 1a, 1b, 1a, 2V, 1a, 1b, 1c | 1a, 1a, 1a, 1c, 1a, 1a, "2b", 2V, 1a, 1b, 1a, 2a, 2''b'', 2a, 1a 2b, 1a || 1a, 1a, 1a, 1b, 1a, 2a, 1a, 1b, 1a, 1a, 1a, 1b, 1a |1a, 1b, 1a, 1a, 1a, 1b, 2a, 1b, 1a, 1b, 1a, 2V, 1a, 1b, 1a | 1a, 1a, 1a, 1c, 1a, 1a, 2b, 2V, 1a, 1b, 2V, 1a, 2a, 2a, 1a || 2b, 1a, 1a, 1c, 1c, 1c, 1a, 2a, 1a, 1c, 1a, 1a, 1a, 1b, 1a | 2V, 1b, 1a, 1a, 1a, 1b, 2a, 1a, 1a, 1b, 1a, 1a, 1b, 1a, 1a | 1a, 1a, 1a, "2a", 1a, 1a, 2b, 1a, 1a, 1c, 1a, 2a, ''2b'', 2a, 1a || 3c, 1a, 1a, 1c, 1a, 1b, 1a, 2a, 1a, 1b, 1a, 1a, 1a, 1b, 1a | 1a, 1b, 1a, 1a, 1a, 1b, 2a, 1a, 1a, 1b, 1a, 1a, 1a, 1b, 1a || 2b, 1a, 1a, 1a, 1a, 1c, 1a, 2a, 1a, 1c, 1a, 1c, 1a, 1c, 1a | 1a, 1c, 1a, 1a, 1a, 1c, 2a, 1a, 1c, 1c, 1a
Tavole
di confronto		 XOmicustos-1   XOmicustos-2
MelodiaThe pitches indicated by the letters differ slightly from the melodic profile indicated by the neumes. At the eleventh syllable of the first line, the letters are 'g-a', whereas the neume indicates a single higher note, which from its heighting would seem to be an 'a'. In the second line at the twelfth syllable, a two-note neume (virga strata) is matched by a single 'g'. Such small differences are consistent with the occasional departures from the melodic profile of the first strophe indicated in the notation added to later strophes. Lines one and two open (e-d-g) and cadence (g-f-d-e) similarly, but are otherwise divergent. It is not possible to observe any melodic repetition in the third line. The use of a sickle-shaped punctum (3.4), which is used at the semitone step both in this notation (1.4) and elsewhere in this manuscript (Aurea personet lyra, see S. Corbin, Die Neumen, 3.107), does however permit tentative reconstruction: for full details, see the discussion and transcription in the book entry for O mi custos.
Trascrizioni storiche
 O-mi-custos O_mi_custos_B412
Edizioni musicali
Leclercq-Bonnes, Jean de Fécamp, pp. 222; Sevestre, Du versus au conduit II, p. 186; Barrett, Ritmi ad cantandum, p. 414

The transcription of the alphabetical notation by Beyssac in the edition of O mi custos presented in the volume by Leclerq and Bonnes departs from the notated letters at 1.9, where the written b should be realised in modern notation as a ‘b flat’. Pitches are also given for the third line without any indication that the reconstruction at that point is a conjectural reading of the neumatic notation since letters were added only to the first two lines.
Sevestre’s realization of the letter notation contains an error at 1.6; the h should be transcribed into modern notation as an a rather than a b. Barrett provides a realization of the letter notation only.
Trasmissione
In the absence of any correlation between the three recorded melodies for O mi custos, it is not possible to speak of melodic transmission in relation to this text, which is in itself a striking result given the survival of three notations for this text from late tenth- or eleventh-century Northern France. What can be said on the basis of the occasional differences between the melodies recorded in neumes and letters in Paris lat. 1928 is that even a locally transmitted melody was subject to alteration.