I would like to learn how to selectively bring out different registers of a musical piece using Audacity 2.0 (Mac OS 6). For example: I would like to play to a student a piano piece using mp3 or Audacity file, but make a certain pitch range stand out (for example, everything up to the middle C) and phase out what’s above it. The result would be he hears primarily the left hand (or the bass/tenor register), and the right hand part is heard softer, or vice versa. What’s the best way to do that, and what other possibilities are there with selective emphasis (bringing out)? Thank you,
What you suggested works more effectively with Low Pass filter. The higher notes of the piano music tend to disappear better because they don’t carry as much low frequency. Lower notes, however, carry higher frequencies/resonance and don’t get filtered away as easily. Is there a way to go around it? (cut the resonance I don’t want?) Or maybe there is another way to filter out things based strictly on note pitch?
Yes, that’s how it works. Every note has a fundamental and harmonics. For example, high-A has a fundamental of 880 Hz, and the A above that has a fundamental of 1760 Hz. If you set your high pass filter to 1700 Hz (so it will filter out everything below the A-1760 Hz), that will allow the second harmonic of the A-880 (which is at 1760 Hz) through, as well as all higher harmonics (which is what I think you mean by “resonance”).
There is no way to separate the second harmonic of A-880 from the fundamental of A-1760. Audacity doesn’t know about “notes”.