Every musician has improvised something that then was unable to remember precisely. With the current technology you can solve that problem: just fire your favorite DAW and click record on a MIDI track. But this system is a bit cumbersome: first of all you have to remember to open your DAW, or have it permanently opened. You need a separate project because probably you are working on other things. So maybe two DAW instances? And you need to open this secondary instance every time you restart your system! Maybe your DAW offers some feature for background MIDI recording, but, does it preserve the data if you close the DAW (or it is closed accidentally)? How easy is to navigate the recorded MIDI data after, say, 3 days, in which you have maybe played at several points of the day?
If you think that there must be an alternative way, you are right!
MIDI Recorder is a little tool that allows you to record into MIDI files everything you play on your MIDI controllers. You can easily set MIDI Recorder to run when your system starts. MIDI Recorder splits what you play based on silences and date/time. You can set up a custom folder and filename structure based on date/time, some characteristics of the the MIDI Input, and other available properties. You can have it running while you work with your favorite DAW.
MIDI Recorder targets .NET 8 and runs on any installed .NET 8 or newer runtime (including .NET 9 and 10). Install the .NET SDK or runtime if you do not already have it.
You can install the tool with:
dotnet tool install -g midirec
You can also install it on a specific folder, but be aware that if you do so you won't have the midirec command
available everywhere:
dotnet tool install --tool-path ./myfolder midirec
MIDI Recorder can work without parameters:
midirec
When called this way, it will record from all your MIDI inputs at once. Every time it detects a pause of 5 seconds in
all the devices, it saves a file with the format yyyyMMddHHmmss.mid in your current directory. While recording,
press m to mark the last saved file as a good impro (renames it with a _good suffix by default). Press any other
key to stop recording.
You can further customize the behavior by specifying the MIDI inputs to be recorded, the delay and the format of the saved filenames.
You can refer to your MIDI inputs by its name or by its index. To know the indexes and names of the MIDI inputs in your
system, use the list verb:
midirec list
You can specify several MIDI inputs separating them by commas:
midirec -i M1,Triton
Finally, as said earlier, you can record all available MIDI inputs if you omit the -i option.
There are three available variables you can use in your path format string:
| Variable | Type | Description |
|---|---|---|
Now |
System.DateTime |
Date and time when the file is saved. |
NumberOfEvents |
System.Int32 |
Number of MIDI events to be saved (including controllers, note-off, after touch, etc.) |
NumberOfNoteEvents |
System.Int32 |
Number of Note ON MIDI events |
Guid |
System.Guid |
A randomly generated unique identifier. |
These variables can be used in your format string using the .NET rules for standard and custom formatting. Take into account that, instead of index numbers, you have to use the full name of the variable. So, for example, you typically use the format strings like:
String.Format("{0:yyyy}/{0:HHmmss}{1}_{2}.mid", Now, NumberOfEvents, Guid);But here you would use instead:
{Now:yyyyMMdd}/{Now:HHmmss}{NumberOfEvents}_{Guid}.mid
The delay to wait without receiving any MIDI activity before saving a file. It is 5 seconds by default but you can use
this option to configure the delay in milliseconds (so for example 8 seconds would be -d 8000).
Resolution of the saved MIDI file in pulses per quarter note (PPQ). Usually it has been 480 (and this is the default when you omit this option), but recent DAWs have started using 960 PPG by default and support even higher resolutions.
After a file is saved, press m in the console to rename the most recently saved file by appending a suffix before
the extension (default _good, so 20260516143022.mid becomes 20260516143022_good.mid). Use --marker to choose a
different suffix, for example --marker _keeper. Pressing m again on the same saved file (before another save) does nothing; each new auto-save can be marked once.
Marking requires an interactive console (it is not available when stdin is redirected).
From the repository root:
dotnet restore src/Icm.MidiRecorder.slnx
dotnet build src/Icm.MidiRecorder.slnx -c Release
dotnet test src/Icm.MidiRecorder.slnx -c Release --no-buildCI runs the same steps on push and pull requests (see .github/workflows/ci.yml). Pull requests that change behavior must update CHANGELOG.md, unless the PR description contains NO_FUNCTIONALITY.
NuGet packages are published by Publish to NuGet when you publish a GitHub Release for tag vX.Y.Z, or manually via workflow dispatch. Configure the repository secret NUGET_API_KEY. For a step-by-step release checklist, use the deploy-release Cursor skill (.cursor/skills/deploy-release/SKILL.md).