The best spectrogram/frequency monitor for Ubuntu Linux: baudline

I tested spek, freqtweak, sndfile-spectrogram (sndfile-tools), jaaa, xoscope, but baudline seemed to be the best one.

Baudline isn't in the Ubuntu repos so you have to download it from the link above.

Since I wanted to analyze a sine wave generated by AMS, I ran baudline_jack (instead of baudline).

Here's a screenshot showing the frequency of a sine wave generated using AMS, using a VCO set to octave 3.

If you mouseover the white left to the left, you'll see the frequency at the right--in this case, a sine wave set to octave 3 in ams generates a tone at ~150 Hz, which is near a D3 note.