What Is an ODF in GrandOrgue?

ODF stands for Organ Definition File — the XML blueprint that tells GrandOrgue how to turn a folder of recorded pipe samples into a playable virtual organ.

When you open a sample set in GrandOrgue (File > Open), you are not opening audio files directly — you are opening the set’s ODF. The ODF describes everything: which samples belong to which stop, how many manuals and pedals the organ has, the stop layout, the graphical console, couplers, the wind model, reverb, and every parameter that makes that particular instrument behave the way it does.

.organ vs .orgue: two packaging styles

• .organ files are the classic format: a single XML file that references a folder of samples and images. Everything must stay in the right relative folders for the organ to load.
• .orgue files are the modern single-file package: samples, ODF, and graphics bundled into one portable file. Download one file, open it, done — much harder to break by moving things around.

Both do the same job; .orgue is simply tidier for distribution. When a sample set page says “GrandOrgue version included,” it usually means the set ships with a ready-made ODF in one of these two forms.

What the ODF controls

Think of the ODF as the organ builder’s workshop notes made executable: stop definitions and voicing, keyboard and pedalboard ranges, the on-screen console layout (which you can tap on touchscreens), enclosure/swell behavior, tracker action simulation, the wind model, and convolution reverb settings. Two different ODFs built from the same recordings can sound and feel like different instruments — the ODF is the instrument, in a real sense.

You can edit it yourself

Because an ODF is plain XML, anyone can open it in a text editor and tweak it: rename stops, adjust the tracker delay, change default couplers, or fix a wrong keyboard range. Always back up the original first, make one change at a time, and reload the organ to test. This is also how community “extended” editions of organs (like the expanded Friesach builds) are made — editors start from the original ODF and improve it. Start exploring with the best free sample sets and install GrandOrgue if you have not yet.

Frequently Asked Questions

What does ODF stand for?

Organ Definition File. It is the XML file that defines how GrandOrgue assembles a sample set into a playable organ: stops, manuals, console layout, wind model, reverb, and all.

What is the difference between .organ and .orgue files?

.organ is an XML file plus a folder of referenced samples; .orgue is a single self-contained package with everything inside. Functionally they describe the same thing — .orgue is just easier to download and share.

Can I edit an ODF myself?

Yes — it is plain XML, editable in any text editor. Back it up first, change one thing at a time, and reload the organ to verify. That is how community extended editions get made.

Where do I get ODFs?

They come with sample sets. Any set listed in our best free sample sets roundup includes a working GrandOrgue ODF.