# Generation of Melodies for the Lost Chant of the Mozarabic Rite
###### Abstract  
Prior to the establishment of the Roman rate with its Gregorian chant, in the Iberian Peninsula and Southern France the Mozarabic ride, with its own tradition of chant, was dominant from the sixth until the eleventh century. Few of these chants are preserved in pitch readable notation and thousands exist only in manuscripts using adiastematic neumes which specify only melodic contour relations and not exact intervals. Though their precise melodies appear to be forever lost it is possible to use computational machine learning and statistical sequence generation methods to produce plausible realizations. Pieces from the Leon antiphoner, dating from the early tenth century, were encoded into templates then instantiated by sampling from a statistical model trained on pitch-readable Gregorian chants. A concert of ten Mozarabic chant realizations was performed at a music festival in the Netherlands. This study shows that it is possible to construct realizations for incomplete ancient cultural remnants using only partial information compiled into templates, combined with statistical models learned from extant pieces to fill the templates. chant; Mozarabic ride; machine learning; statistical language models; music generation +
Footnote †: journal: Medical  
the melodic contour of the pitches internal to each neume. From note to note it is usually apparent if the melody goes up or down [3]. This contour information can be represented using six letters: h, a note higher than the previous note; l, lower; e, equal; b, higher or equal; p, lower or equal; o, a note with unclear and undefined relative height. Figure 1 shows a fragment of the _Canticum Zachariae_ for the least of [PERSON]. Shown at the top of the figure are two lines from the Leon antiphoner. Following that is the transcription of the neumes on the bottom line to contour letters. In the contour sequence syllables are separated by dashes and words by spaces. Finally the figure shows a passage of a performance score with a generated compatible melody (see Results). Another important feature of chant is the presence of recurring _intra-opus_ patterns within single chants [4] that would seem to represent the same melodic content in the lost chant, for example, the encircled neumes and bracketed contour sequence in Figure 1. There is a wide consensus among chant scholars that longer (i.e., 20 or more notes) intra-opus patterns do represent the same sequence of pitches [5]. Therefore in generated pieces, an _intra-opus_ pattern should be instantiated by the same musical material. Repetition is ubiquitous in music and the generation of music containing repetitions is an important open topic in the area of music informatics, because it requires the solution of equality constraints between distant events in the music surface [6; 7]. The core task of the adiasematic neume realization problem is to find pitches compatible with a specified template consisting of the melodic contour and intra-opus patterns. Since a vast number of melodies will be compatible with a given template, this is a highly under-constrained problem. Therefore a position must be taken on whether the task is viewed more as _restoration_ or more as _generation_. Some scholars have shown melodic relations with other chant traditions for some specific Mozarabic chants [8]. In such cases chant realization may be approached as primarily a _restoration_ task: using long fragments of concrete pitches found in a chant with known pitches and presumably with a historical relation. This is one motivation of the method of [PERSON] [9] for chant generation, which searches a corpus of preserved chants using contour descriptions of phrases from the template. If a closely matching database piece exists, it is used to overlay pitched fragments on the new chant. Remaining regions of the chant are constructed using less stringent matches. Finally manual editing of the borders between phrases will complete the melody.