BLE MIDI makes MIDI wireless, by sending MIDI messages over a Bluetooth Low Energy connection - which makes it a great solution for art & performance applications. The latest versions of Windows and MacOS, & iOS support the BLE MIDI standard.
BLE MIDI is a good fit for smartphones & tablets which are usually lacking in the hardware connectivity department. Many mobile music apps such as Apple's Garageband include support for BLE MIDI devices, and Android users can add support using third-party apps.
Because of Bluetooth Low Energy's limitations, BLE MIDI messages will take longer to arrive at their destination compared to a wired MIDI connection. The time will vary based on circumstances such as signal strength, proximity, etc., but you can expect a BLE MIDI message to have about 10-20 milliseconds (ms) of latency between the time a message is sent and when it is received. This is significant when compared to USB MIDI's ~3ms latency.
Next, we'll look at how to program a Feather Bluefruit nRF52 board for use as a BLE MIDI controller.