Make note/chord detection easier

[CBerthy]

Thanks for your work on Friture, I like it :-)
I often need to detect what note/chord and rythm is played when studying a song or designing sounds on my synths.
Friture Spectrogram is nice, promising and may already help me.
However it would be great if:

• a piano keyboard with note labels could be added instead (or in addition to) the frequency scale on the left. It would then be shown/hidden with a direct click with a very accessible button
• an easier and direct way to zoom and unzoom vertically and horizontally on Spectrogram window (and then why not the others ;-))
• a grid in the background to easily match the notes with the spectrogram segments
  I definitely know the limitations of detecting notes/chords when the sound is "noisy' but in that case I would use filters or even stem-splitter to purify the sound before.
  Hope that could be taken into consideration :-)

Thank you again.