Audio-to-Score Alignment System to Synchronize Medieval Chant Recordings
54º Congreso Español de Acústica — Tecniacústica 2023
Abstract
Medieval music has been systematically studied by scholars for over a century. Nowadays, extensive databases exist that contain transcriptions of Gregorian chants in GABC format. These databases often include additional media such as images of the original manuscripts or audio recordings of the chants. In this paper, we propose an audio-to-score alignment system to synchronize a chant in GABC format with its corresponding audio rendition. First the GABC score is converted into MIDI using fixed values for tempo and note duration (markings like punctum mora and episema are taken into account). The MIDI score is then aligned to the audio by computing a full pairwise distance matrix between audio and score sequences, and using a version of offline Dynamic Time Warping, which is very efficient in terms of memory and CPU. As a result, each single square-note (and its Latin syllable) is assigned a precise time within the audio performance. Our system demonstrates strong resilience towards variations in tempo and note duration, but unfortunately does not work with unison chants.