I am working on a project to make a synthesizer for RaspberryPi capable of playing Harmonium/Reed Organ using an external MIDI keyboard. I am making it in Python 2.7 using NumPy. Till now, I have completed first phase of my project which includes building UI and primary synthesis script, interfacing with keyboard and mapping notes with keys. In my second phase I am planning to move it to RaspberryPi from PC and improving sound quality.

For synthesizing Harmonium sound in first phase, I recorded Harmonium samples and did Fourier transform on it and extracted out dominant frequencies from it and then wrote synthesis function by adding sine waves of those frequencies. However the generated sound is okay for testing, but it is not at par with original Harmonium sound, which is inevitable for final version of the project. Thus I request to suggest me the techniques to generate Harmonium sound. Also is it possible to generate with Oscillators, Filters etc.. which is available in Helm Synthesizer? And if yes, then how to tune them so as to generate perfect Harmonium wave? Please help me as I am beginner in this field.


NB : I have asked this question on music.stackexchange.com, but due to a suggestion from there I have placed the question here, hoping to get some help.

  • I know this is an old thread, but I wanted to ask how you are getting on with this? I'm in the middle of a very similar process but I've approached it from the opposite way - beginning with simple synth shapes and blending them, before using multiple band pass filters to try and emulate reed sounds. I guess the difference at my end is I'm not trying to create an exact copy of any reed instrument per se, just trying to build a Synthesizer well suited to accompanying folk singing. I'm fully in the box right now (Ableton), but once I've settled on the requirements I was planning on using helm on Commented May 28, 2022 at 6:35
  • SE does not have the concept of threads - please only use answer posts for answers.
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    Commented May 30, 2022 at 11:36

1 Answer 1


I later recorded the base note/frequency (C4) and resampled it to other notes. Although the quality is not studio level, it is still pleasant. A good recording sample would improve quality. Finally, I built Command Line and GUI version (for Pi) of the synthesizer.

Refer my project code on GitHub: Synthesizer

Alternate answer to this question on Music Portal: https://music.stackexchange.com/a/62334/44420

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