#58 Measurement option of portamento and vibrato speed

[JuleeHong]

Spectrogram gives good definition on the time axis, and is consequently particularly useful for analysing time related expressive parameters such as portamento and vibrato speed in non-keyboard instrument performances.

Spectrogram:
1. Click the portamento and/or vibrato within spectrogram
2. SV provides the readings of portamento and vibrato speed of the chosen parameters