TeensySynth - a polyphonic MIDI synthesizer for Teensy 4.x

Forked from https://github.com/jmechnich/TeensySynth

Changes from original fork

• modified as needed to support teensy 4.1 and multiple MIDI input devices. allows a keyboard to control notes and a separate control surface to control synth parameters* features three poscillators per voice, each with tuning and volume
• use teensyduino's new bandlimit waveforms to eliminate aliasing
• added filter envelope
• added noise generator
• LFO
• sample and hold
• misc playability fixes. allow retrigger of notes when sustain is held. in mono mode retrigger still-held notes when current note is released.
• reorganized CC changes into a mapped array. created a mapped array for all parameters.
• patch save/load/select into micro SD card on Teensy 4.1
• added optional support for inexpensive teensy 320x240 TFT touchscreen
• added support for inexpensive PT8211 DAC or MAX98357 DAC instead of Teensy Audio Shield
• added reverb
• added support for optional potentiometers for volume, filter, and resonance

Useful links

• Teensy Audio Library
• Audio System Design Tool for Teensy Audio Library
• MIDI controller number