Casio CTX 870IN is a powerful arranger keyboard that supports USB MIDI, allowing you to connect it to various devices and apps. One such popular app is MIDI Commander — a free Android app that can send custom MIDI commands to control external hardware like keyboards, synthesizers, and software instruments.
In this post, we’ll guide you step-by-step on how to set up and use the MIDI Commander app with your Casio CTX 870IN.

🎯 What You’ll Need
Before you begin, make sure you have the following:
- ✅ Casio CTX 870IN keyboard
- ✅ Android smartphone or tablet
- ✅ USB OTG (On-The-Go) cable
- ✅ standard USB printer cable
- ✅ MIDI Commander app (download from Google Play Store)
🔌 Step 1: Physical Connection
- Connect the printer cable on the back of your CTX 870IN in USB port .
- Plug the other end of the USB cable into your OTG adapter.
- Connect the OTG adapter to your Android device.
If everything is connected properly, your Android phone will detect the Casio keyboard as a MIDI device.
📲 Step 2: Install and Launch MIDI Commander
- Go to the Google Play Store.
- Search for MIDI Commander and install the app.
- Open the app — it will ask for permission to access USB devices. Tap “Allow”.
⚙️ Step 3: Setup MIDI Commander
Once inside the app:
- Tap on “Settings” > “MIDI Device” and select your Casio CTX 870IN.
- Choose or create a Custom Layout of buttons to send MIDI messages.
- Assign functions like:
- Program Change (to change tones)
- Control Change (to control effects)
- Note On/Off (to trigger sounds)
- Bank Select (to access tones across banks)
🎵 Example: Assign a button to send Program Change 25 — this could change the tone to a Piano or Organ depending on the tone map of CTX 870IN.
Read more on MIDI Commander app
🎚️ Step 4: Using the App in Real-Time
Now you can:
- Use your phone as a MIDI controller to change tones or rhythms.
- Create custom foot pedal simulations (great for performers).
- Control volume, pitch bend, or modulation remotely.
This setup is especially helpful during live performances or complex layer setups.
🧠 Pro Tips
- 💾 Save different layouts for different songs or performances.
- 🔄 You can also use it with DAWs like FL Studio Mobile or BandLab.
- 🔋 Make sure your phone has enough battery or is plugged in — MIDI over USB can drain it quickly.
❓ FAQs
Q: Can MIDI Commander change rhythms on CTX 870IN?
A: Not directly. Casio doesn’t offer full SysEx documentation, so only limited control (like tone/program change) is possible via MIDI.
Q: Does MIDI Commander work on iPhone?
A: No, it’s an Android-only app. iOS users can explore apps like MIDI Designer or TouchOSC.
Q: Can I control layer/split settings via MIDI?
A: Advanced features like layers/splits usually require SysEx commands, which Casio doesn’t fully expose for CTX series.
🎼 Final Thoughts
Using the MIDI Commander app with your Casio CTX 870IN opens up new creative possibilities for live performance, practice, or studio use. While Casio doesn’t allow full MIDI control, tone switching and basic performance control can be a huge help.
If you found this guide useful, make sure to share it, and check out more keyboard tips on HavenMusicals.com!