How to install python-rtmidi from source on Windows

These instruction should work for installing python-rtmidi from source Python 3.x in the 64-bit or 32-bit vsersions (you can run the latter on Windows 64-bit versions with no problems).

Please follow all the steps below in the exact order.

Installing required software

You probably need administrator rights for some or all of the following steps.

  1. Install the latest release of Python 3.5+ from to the default location (e.g. C:\Python35). You can install either or both the 32-bit and the 64-bit version.

    In the installer, enable the option to install pip. Optionally, for only one of the chosen Python versions, enable the options to add the installation directory to your PATH and set it as the system’s default version. Also enable the option to install the py helper script (only available with some Python versions).

  2. Install virtualenv from a command prompt:

    > python -m pip install -U virtualenv

    Repeat this for all Python versions you have installed (run py --help to get help on how to run different python version from the command line).

  3. Go to and follow the instructions there to select and install the correct version(s) of the Visual C++ compiler for the version(s) of Python you installed.

    You can install several versions of Visual C++ at the same time.

    After installation, use Windows Update to get any pending security updates and fixes.

Setting up a virtual environment

  1. Open a command line and run:

    > python -m virtualenv rtmidi
    > rtmidi\Scripts\activate
  2. Update pip and setuptools within your virtual environment to the latest versions with:

    (rtmidi)> pip install -U pip setuptools
  3. Install Cython (still in the same command line window):

    (rtmidi)> pip install Cython

Download & unpack python-rtmidi source

Get the latest python-rtmidi distribution as a Zip archive from and unpack it somewhere. You can do the downloading and unpacking in one step using pip:

> pip install --no-install -d . "python-rtmidi"

Alternatively, clone the python-rtmidi git repository:

> git clone

In the command line window you opened above, change into the python-rtmidi directory, which you created by unpacking the source or cloning the repository:

(rtmidi)> cd python-rtmidi

Build & install python-rtmidi

Just run the usual setup command from within the source directory with the active virtual environment, i.e. from still the same command line window:

(rtmidi)> python install

Verify your installation

Change out of the python-rtmidi source directory (important!) and run:

(rtmidi)> cd ..
(rtmidi)> python
>>> import rtmidi
>>> rtmidi.API_WINDOWS_MM in rtmidi.get_compiled_api()
>>> midiout = rtmidi.MidiOut()
>>> midiout.get_ports()
['Microsoft GS Wavetable Synth']

If you have any other MIDI outputs (hardware MIDI interfaces, MIDI Yoke etc.) active, they should be listed by get_ports() as well.

That’s it, congratulations!


Windows Kernel Streaming support in RtMidi has been removed (it was broken anyway) and consequently in python-rtmidi as well.

Compiling with MinGW also does not work out-of-the-box yet. If you have any useful hints, please let the author know.