Properties of violin glides in the performance of cadential and noncadential sequences in solo works by Bach

This study examines the articulatory changes ('glides') between the leading tone and tonic of cadential vs. noncadential semitone sequences in solo violin performance. It was predicted that though these glides would have similar slopes, they would differ in duration and in semitone intonation, and that these latter properties could characterise the expression of cadential finality and the structural insignificance of noncadential sequences. Cadential (46) and noncadential (58) targets from 17 recordings by 13 professional violinists were analysed using narrow-band spectrograms. Glide durations comprised 6.9% of the overall duration of semitone sequence irrespective of structure function. However, cadential glides comprised 28% of the duration of the leading tone compared with 11% for noncadential glides. As predicted, the leading tone tended to be sharp in both contexts, but the mean cadential interval was nonsignificantly larger by 18 cents, mainly because the tonic tended to be tuned more accurately in cadential sequences. Finally, the glide direction was linear and followed the natural vibrato trajectory in both contexts as expected. These data confirm that articulatory modifications play a prominent role in the performance of intended musical structure and suggest that such distinctions will influence structural expectancies.