Installing Music21 in Windows

Get Python

Python is a simple but powerful programming language that music21 is written in and in which you will write your own programs that use music21.

Windows users should download and install Python version 3.4. Python 2.7 is still supported, but if you’re learning Python for the first time, definitely go for Python 3.X.

To get Python 3.4 for Windows, go to and click on the “Windows installer” link. It is probably the first link. Save the file to your desktop and then click on it there.

To test to see if Python has been installed properly, go to the start menu and run (either by clicking “Run” in older Windows or by typing in the search box) a program called IDLE. Once it’s started, type 2+2. If your system then displays 4 python is working properly and we can start thinking about installing music21.

Updating Python

If you have already installed Python on your computer, launch IDLE (a Python interpreter and code editor) by clicking the start menu and clicking Run (on Windows XP or older) and typing in “IDLE” or (on Windows Vista and newer) typing in “IDLE” in the Search Programs list.

The first lines of text displayed will include a version number. Make sure it begins with 2.7.3 or higher or 3.3 or higher.

If your version is too old, download a newer version as above.

Download music21

Download the most-recent music21 package from the following URL:

Windows users should download the .exe file to their desktops and then click on it.

Install music21

Windows installation is easy. After downloading the music21.exe installer, click on it on your desktop, then follow and accept the prompts for default install options. This installer simply copies files into the Python site-packages directory. If the installer quits without further notice the installation has been successful.

To test to see if music21 has been installed properly, go to the start menu and run (either by clicking “Run” in older Windows or by typing in the search box) IDLE. Type “import music21”. If your system waits for a few seconds and then displays “>>>” and perhaps a warning about missing packages, then you’ve installed everything properly. (If the system cannot find music21 then you may have more than one version of Python on your system. Try uninstalling all of them along with music21 and then restarting from scratch).

After Installation

After a successful installation, you may proceed to Notes to begin using music21.

Installation Help

If you have followed all the instructions and still encounter problems, start over from scratch and try it again very carefully. If you still have problems contact the music21 group and someone should be able to help: