Use a Nintendo Power Glove and Feather Sense running CircuitPython make a BLE MIDI synth gesture controller!
Use the four finger flex sensors in the Power Glove to send MIDI CC, Pitch Bend, or NoteOn/velocity info to your BLE MIDI synthesizer, including apps on iOS and computers. The Feather Sense nRF52840 has Bluetooth LE built in, as well as an on-board accelerometer used for tilt sensing.
No Power Glove? No problem -- build it with new flex sensors and your own glove.
You'll need the following parts for the build, including a Nintendo Power Glove, which you may have in your basement, or find at an auction online.
If you don't have a Power Glove, you can alternately build a BLE MIDI controller using any nRF52840 board and some flex sensors. These alternate boards also lack the accelerometer that's built onto the Feather Sense.