Can I use my Android phone as a MIDI keyboard?

What is a MIDI Keyboard?

A MIDI keyboard is an electronic musical keyboard that doesn’t produce sounds on its own, but instead transmits Musical Instrument Digital Interface (MIDI) data to other devices like computers, tablets, and sound modules (Source: https://robots.net/digital-media-and-creative-tech/content-creation-tools/what-does-a-midi-keyboard-do/). When you play notes and chords on a MIDI keyboard, it sends MIDI messages that trigger and control sounds and software instruments on the receiving device.

MIDI keyboards connect to Digital Audio Workstations (DAWs) or music production software either wirelessly via Bluetooth or using a USB cable. The keyboard acts as a MIDI controller that plays virtual instrument plugins within the DAW, so you hear the sounds coming from your computer speakers or headphones rather than the keyboard itself. This allows you to access a wide variety of realistic instrument sounds, from pianos and strings to synthesizers and drum kits (Source: https://robots.net/digital-media-and-creative-tech/content-creation-tools/how-does-a-midi-keyboard-work/).

Using an Android Phone as a MIDI Controller

There are several apps that allow you to turn your Android phone or tablet into a MIDI controller to use with music production software and hardware synthesizers. Some of the most popular options include:

TouchDAW – A full-featured MIDI and DAW control app with MIDI routing and wireless control capabilities (https://www.synapticsound.com/android-midi-controller/).
MIDI Control – A simple app to convert your Android device into a MIDI controller using a WiFi connection.
Lemur – A customizable MIDI and OSC control app that works over WiFi.

MIDI Commander – Another customizable control surface app for MIDI control.

These apps allow you to map your phone’s touchscreen and other sensors to MIDI controls like notes, CCs, program changes, transport functions, and more. You can customize the interface with faders, knobs, keys, pads, and buttons.

Some key advantages over dedicated MIDI keyboards and controllers include:

Portability – You have a MIDI controller with you at all times on your phone.
Customization – The interface can be tailored to your needs.
Cost – No need to buy additional hardware.

However, there are some downsides:

Smaller interface than a MIDI keyboard.
No tactile feedback like on real keys and buttons.

Potential latency issues depending on WiFi and app.

Setting Up the MIDI Connection

Connecting an Android phone to a computer with a MIDI interface is relatively straightforward. You will need a USB OTG (On-The-Go) cable or adapter to connect your Android device to a USB MIDI interface or MIDI keyboard. The OTG cable allows the Android device to act as a USB host.

Once connected, you may need to enable MIDI support in your Android device’s developer options. Go to Settings > Developer options and check the box for “MIDI” under the Select USB Configuration menu (source). This allows the Android OS to recognize the MIDI device.

There are also wireless options for connecting an Android phone to a MIDI device. Some MIDI keyboards and interfaces have built-in Bluetooth support. You can pair your Android phone to the MIDI device via Bluetooth and transmit MIDI wirelessly. Low latency Bluetooth MIDI adapters like the Yamaha MD-BT01 are also available.

For longer wireless ranges, Wi-Fi MIDI adapters can connect your phone and MIDI device over your local network. Apps like midiBeam transmit MIDI over Wi-Fi with decent latency. Some other wireless options include using an audio interface with Wi-Fi and streaming MIDI over an ad-hoc network from your phone.

Overall, USB OTG provides the most reliable wired connection, while Bluetooth is likely the simplest wireless option. With some adapters and configuration, wireless MIDI from an Android phone is certainly feasible.

Mapping Sounds and Controls

Once you have a MIDI connection established between your Android device and your synthesizer or DAW, the next step is mapping sounds and controls to your phone’s screen. Here are some tips for mapping effectively:

For playing melodic instruments like piano or guitar, map each key or string to a button on your phone’s screen. Most MIDI controller apps have a keyboard view that lets you map each piano key to a button. For drum kits, map each drum pad or cymbal to a button for finger drumming. Consider offsetting buttons like drum pads to match the layout of real drum kits.

You can also map modulation controls like pitch bend or volume to slide controls on your phone screen. Assign parameter dials in your synth to knobs or sliders. Map sustain pedals and other momentary buttons to your phone’s buttons for easy triggering.

Some MIDI controller apps like DAW It allow advanced mapping of notes, controllers, program changes and more to build highly customizable rigs.

Take time to set up mappings that feel intuitive for your workflow. Group related functions together and use screen space efficiently. Remember you can remap controls at any time as you customize your mobile MIDI experience.

Latency Considerations

When using an Android phone as a MIDI controller, latency can be an issue, especially with wireless connections. Latency refers to the delay between pressing a key on the phone and hearing the sound come out of your speakers or headphones. A high latency makes it difficult to play in time and get accurate timing.

With a wired connection over USB, latency can usually be managed to acceptable levels below 10ms. However, with wireless Bluetooth MIDI, latency is often much higher in the 30-100ms range (Source). This makes Bluetooth virtual MIDI keyboards nearly unusable for live performance or recording.

There are a few tips to reduce latency when using an Android phone as a wireless MIDI controller:

– Use optimized apps designed for low latency like MIDI Tools or MIDI Controller (Source). The app architecture makes a big difference.

– Connect audio interface directly to speakers/headphones rather than piping through the phone. This avoids Android audio latency.

– Use Android phone with Snapdragon 865/888 chipset rather than slower processors.

– Turn off power saving mode, WiFi, Bluetooth, and background apps to optimize Android OS.

– Position phone as close as possible to Bluetooth MIDI receiver. Longer wireless distance increases latency.

– Use OTG cable for wired MIDI connection rather than Bluetooth if latency is critical.

Best Android Phones for MIDI

When choosing an Android phone to use as a MIDI controller, it’s important to consider phones with low audio latency capabilities. Low latency allows for more responsive and accurate MIDI note triggering and control, resulting in a better playing experience. Phones like the Samsung Galaxy S21 line and Google Pixel 6 Pro tend to have lower latency due to their more powerful processors.

Larger screen sizes are also ideal for MIDI keyboards and drum pads, as they allow for more keys, pads, and controls to be displayed and used. Phones with screen sizes 5.5 inches or larger, such as the Galaxy S21 Ultra or Google Pixel 6 Pro, provide enough space for a full 88-key piano keyboard and other interfaces. Smaller screens can still work but may feel more cramped and limited.

Overall, Android phones like the latest Galaxy S21 series or Pixel 6 Pro offer a combination of low latency audio, fast processors, and large, high-resolution screens that make them excellent choices to use as MIDI controllers.

Top Recommended Apps

There are a few key apps that stand out for using an Android phone as a MIDI keyboard and controller.

MIDI Controller Apps

Apps like MidiCommander allow you to use your Android device as a MIDI keyboard and controller. You can customize the on-screen keyboard layout, assign MIDI control messages to on-screen faders and buttons, and control multiple external synthesizers.

Another popular option is MIDI Keyboard, which provides an 88-key on-screen piano you can play via the touchscreen. It connects to external MIDI devices over WiFi, Bluetooth or USB.

MIDI Bridge Apps

Apps like MIDI Bridges allow you to route MIDI data between apps on your device as well as to/from external MIDI devices. This enables using one app to generate the MIDI data and another to respond to it.

Useful features include MIDI merging and filtering, virtual MIDI ports, and customizing MIDI channel and controller mappings.

DAW Apps

Full featured DAW (digital audio workstation) apps like Caustic 3 provide sequencing, synthesis, sampling and effects to produce full tracks on your Android device. You can record and manipulate MIDI data, trigger loops and one-shot samples, and route everything flexible with MIDI.

Limitations to Consider

While using an Android phone as a MIDI controller offers plenty of benefits, there are some limitations to be aware of compared to a full-sized MIDI keyboard controller:

Smaller screen size – The smaller screen on a phone limits the number of controls and parameters that can be easily accessed compared to a full-sized MIDI keyboard. This can make detailed editing and tweaking more difficult.

Limited controls/parameters – Most mobile MIDI apps provide basic controls like keys, pads, knobs and faders. But full MIDI keyboards often include additional buttons, sliders, wheels and controls for deeper manipulation of sounds.

Audio latency challenges – Sending MIDI data from the phone to an external synth introduces latency (delay between playing a note and hearing it). Optimizing audio settings can reduce latency, but may not fully match the real-time feel of a MIDI keyboard.

As explained on Quora, while an Android phone can work well for basic MIDI needs, critical timing applications or live performance may benefit more from a full-sized MIDI keyboard controller.

Use Cases and Recommendations

Using an Android phone as a MIDI controller offers some unique benefits in certain use cases:

Portable rig – An Android phone is ultra portable, allowing you to have a MIDI controller with you at all times without having to carry around a bulky keyboard.

Supplemental controls – Phones can provide supplemental knobs, faders, keys for more flexibility when used alongside another MIDI keyboard.
Mobile music making – Using a phone for MIDI when traveling or making music on the go.
Budget option – If you can’t afford a MIDI keyboard, an Android phone can be a cheaper alternative.

However, there are some situations where a real MIDI keyboard is still advised:

Playing piano or keyboard focused music – For piano players, the tactile feedback and precision of a real weighted keyboard can’t be replicated on a phone screen.
Complex arrangements – A full sized MIDI keyboard with more controls will be better for intricate arrangements.

Recording studios – The low latency and seamless integration with other gear makes pro MIDI keyboards preferable for studio use.
Live performance – For reliability and physical feedback on stage, a real keyboard is advisable over a phone-based rig.

In summary, Android phones work well for portable and casual use, while serious musicians playing live or recording in the studio will likely still want the quality of a professional MIDI keyboard.

The Future of Mobile MIDI

Mobile MIDI capabilities are likely to improve significantly in the coming years thanks to emerging technologies like 5G. As reported at NAMM 2020, 5G networks will greatly reduce latency when using MIDI controllers wirelessly with mobile devices and computers (source). This very low latency opens up many new possibilities for mobile music production and performance.

With 5G and continued advancements in mobile processing power, mobile devices will become even more capable MIDI controllers. Musicians will be able to produce music and perform live sets wirelessly using just their smartphone or tablet as a control surface. Reduced latency means musicians can play virtual instruments and synthesizers on their mobile devices with precise timing and response.

As mobile MIDI matures, expect more sophisticated MIDI protocol support, improved wireless connectivity, reduced power consumption, and innovative control methods leveraging a phone’s touchscreen, sensors, and peripherals. Mobile devices may even replace traditional MIDI keyboards and controllers for many musicians in the not-too-distant future.