Mel-spectrogram and Chroma STFT plots
Pluto spends additional time plotting various Spectrograms because the augmentation technique is the same as in the Waveform graph in Chapter 7. Pluto will write fewer new wrapper functions. He will reuse the methods from the previous chapter, but before that, let’s draw more Spectrograms.
The subjective unit of pitch, also known as the mel scale, is a pitch unit with equal distance between pitches. S. S. Stevens, John Volkmann, and E. B. Newmann proposed the mel scale in the scholarly paper titled, A scale for the measurement of the psychological magnitude of pitch, in 1937.
The math calculation for the mel scale is complex. Thus, Pluto relies on the
melspectrogram() method from the Librosa library to perform the computation. The Pluto
draw_melspectrogram() wrapper method uses the Librosa
melspectrogram() function, and the code snippet is as follows:
# code snippeet for the melspectrogram mel = librosa.feature.melspectrogram(y...