MIDI on the Run: MIDI Opener for iOS

Finally, a computer-related topic…

As I’ve established in my OpenMPT post and various vintage computer emulators (DOSBox and Basilisk II), I enjoy listening to MIDI files.

I used my first cell phone, an LG Optimus Elite, to play MIDI files on longer trips. The MIDI files would fit in the extremely tiny storage of the Optimus Elite, and would allow me to continue listening even when the reception was spotty. I had over a dozen downloaded MIDI files of my favorite songs on the phone.

But I didn’t just listen to MIDI on the run… I also listened to it on our computer. From time to time I would use a website like Solmire to edit the MIDI file, changing instruments or the pitch. I would also listen in OpenMPT.

After the Optimus Elite, though, I no longer played the MIDI files on my cell phone… that is until now.

There are many different MIDI players or “soft-synths” on the iOS App Store. Some are free, others are not. Some are extremely basic while others are quite detailed and rival OpenMPT in the amount of detail displayed.

One day I was bored and playing around with my iPad and decided to try finding a MIDI app. The first one I found and tried was Sweet MIDI Player by Roni Music. The free app was good and fairly detailed, although the free version cuts off the last quarter of the song – forcing you to fork over $15 if you wanted to play the entire song. Wanting a free (but decent) alternative, I uninstalled it and tried something else.

Which brings me to…

MIDI Opener

One of the free MIDI apps was MIDI Opener by Seanote Factory. Compared to some of the other apps (including Sweet MIDI Player,) this app was extremely basic. So basic the only controls is opening a file, play/pause, a timeline and a repeat setting.

Despite MIDI Opener’s spartan interface, it does a fairly decent job playing most MIDI files on an iPhone, iPad or iPod.

Despite the simplicity, MIDI Opener does the job. About the only thing it doesn’t do that it said it would is be able to connect to Google Drive, so I had to load my MIDI library into iCloud. My other complaint is that there are missing instruments, and some of the other instruments sound really bad. But on *most* MIDI files this isn’t a problem.

I was so impressed that I installed MIDI Opener on my iPhone 6S.

While MIDI Opener plays most MIDI files flawlessly, I did notice there was one or two files in my library it struggles with. My usual William Tell Overture test file would only play about a minute on my iPhone 6S. On the iPad, it would play the entire file – but not without struggling.

Here’s a couple files played by MIDI Opener, and recorded using the IBM ThinkPad T42.

The failed attempt at recording the “William Tell Overture” playing in MIDI Opener on the iPhone 6S
R.E.M.’s “Nightswimming” being rendered by MIDI Opener on the iPhone 6S

MIDI Space

I decided to try another free MIDI app for iOS: MIDI Space by Derrick Ward. Unlike the other two, MIDI Space doesn’t have any ratings on the App Store.

MIDI Space is a free MIDI app that provides a graphical view of the MIDI notes being played. MIDI Space also has support for connecting your device to a MIDI instrument or other MIDI hardware.

MIDI Space has support for MIDI In/MIDI Out ports, as well as Bluetooth devices.

MIDI Space has an excellent 3D view of the notes being played, as well as upcoming notes. The app allows you to reposition the camera, so that you can get multiple different angles.

From the top…
From the left side…
From behind…

Unfortunately, MIDI Space has a lot of missing instrument samples. One test file I normally play when trying a new soft-synth is a MIDI rendition of R.E.M.’s “Nightswimming.” MIDI Space is the first MIDI app or soft-synth unable to play Nightswimming properly.

And it’s a shame, too, since it’s the only truly free MIDI app I could find that provided a graphical view of the notes and had MIDI In/Out support.

MIDI Space also doesn’t allow you to scrub around in files (it has a timeline but you can’t skip around in the song using it.) There are some bugs in MIDI Space, too. First, if you pause a file, the graphical note view restarts from the beginning when you resume playing the file, despite the music actually starting from where it was paused. MIDI Space will also crash if you try to open a different song while one is playing.


If you’re looking for a free iOS MIDI app that gets the job done and plays MIDI files from your library, I highly recommend MIDI Opener by Seanote Factory. Don’t let its simple interface fool you… it renders most MIDI files fine.

If you’re looking for something that has a graphical interface or displays more advanced information, I’d recommend looking at one of the paid apps.