This shows a possible use of pitch.js
This demo references its dependencies as git submodules. Get the code and all submodules in one go:
git clone --recursive https://github.com/audiocogs/pitch.js-demo
If you have already cloned the repository without the --recursive option you also need to update the submodules
git submodule init
git submodule update
Browsers put restrictions on file:// and demo will not work if you open the file directly. You need to set up a web server on your machine.
If you have Python 3 installed, run the following from the repository's directory:
python -m http.server
Or, with Python 2:
python -m SimpleHTTPServer
The demo will be available at http://localhost:8000/ui.html. Allow microphone access in the flash settings dialog that appears. The browser itself might ask for confirmation (Chrome does that), allow microphone access again.
Try singing something! You should see the frequency change. If nothing happens, you're not singing loud enough — connect an external microphone or get closer to the one integrated in your computer.