Frequently Asked Questions

Thank you for using NS MIDI Player! This page contains answers to some frequently asked questions about NS MIDI Player. If you have any other questions, please feel free to contact me.

Q: How do I connect to a Bluetooth MIDI device?

A: Here's what you need to do to connect to a Bluetooth MIDI device:

  1. After opening the app, tap the output picker (it will initially say "Default SoundFont")
  2. In the sheet that pops up, go to the "MIDI Outputs" section and then tap "Search for Bluetooth MIDI Devices." You may need to scroll to see it.
  3. If the app asks to use Bluetooth, make sure to press "OK" to allow access.
  4. Your device should show up in the list. Tap that list item to connect to it. If you don't see your device, make sure that it is plugged in, turned on, etc.
  5. Once it says that you're connected, tap the Back button. You should now see your device under the "MIDI Outputs" section. Tap it to choose it as the MIDI output.

Q: What is included in the full version of NS MIDI Player?

A: Upgrading to the full version of NS MIDI Player gives you access to these features:

This is a one-time purchase shared across all of your devices and helps support further development. All other features are free.

Q: I am previewing a large number of MIDI files with Quick Look, and I want them to play automatically when I use the arrow keys in the Finder. How do I do this?

This answer applies to macOS only.

A: By default, the Quick Look preview will only play files when the large Quick Look preview window is brought up, either by pressing Space with a file selected, or by choosing "Quick Look" in the menu. This matches system behavior.

However, if you have the preview pane visible in the Finder (you can make it visible with View menu > Show Preview or Command-Shift-P), you can change this behavior so that it will automatically play the selected file in the preview when you use the arrow keys. Here is how to do this:

Open the Terminal app and run the following command (paste the command in, then press Return to run it):

defaults write com.nitinseshadri.midiplayer.qlextension autoplay_preference -bool true

There is one side effect: if you have the preview pane open, the files will automatically play as soon as you click on them, so you'll need to hide the preview pane if you don't want that to happen. However, the large preview window should work as expected.

Note that the Auto-Play setting in the main app will not affect the Quick Look preview. You'll need to use this method instead.

Future versions of the app will make this configuration process easier. Please let me know if you have any questions or feedback!

Q: I am trying to preview drum MIDI files in Quick Look, but I hear a piano sound instead. How do I fix this?

This answer applies to macOS only.

A: This requires a bit of explanation. First, why it happens, and second, how to fix it.

Why this happens: Many drum loop MIDI files place their MIDI events on channel 1. This is fine when importing them into a DAW (e.g. Logic Pro), as you can drag them into the DAW and choose the MIDI channel and instrument per track. However, NS MIDI Player is a General MIDI compatible player, and in the GM standard, channel 1 (and all channels besides channel 10) are melodic channels, and channel 10 is earmarked for percussion. Therefore, when such a file is previewed, you will hear piano sounds, because the default instrument for all melodic channels is piano.

How to fix it: The following workaround redirects all MIDI events in a previewed MIDI file to the percussion channel, channel 10. It can be enabled through temporary settings that you will need to access via the Terminal app. Here is how you can enable it:

Open the Terminal app and run the following commands (paste each line in, then press Return to run it):

defaults write com.nitinseshadri.midiplayer.qlextension NSXRedirectEventsToSingleChannel -bool true
defaults write com.nitinseshadri.midiplayer.qlextension NSXRedirectEventsChannel 9

For the curious: You can change which channel the MIDI events are sent to by changing the number in the second command. The numbering starts at zero (for channel 1) and goes until 15 (for channel 16). Channel 10 (9 in the command) is the percussion channel. Also, you can disable this behavior by changing "true" to "false" in the first command. Changes take effect the next time a MIDI file is previewed.

Future versions of the app will make this configuration process easier. Please let me know if you have any questions or feedback!

Q: I am running an older version of macOS. Where can I find old versions of NS MIDI Player?

A: Download old versions of NS MIDI Player for Mac here.