One project I found interesting was a Juke Box project that someone had made using the Arduino program. You can insert a coin into it and select the song you want to hear, which is stored in a mp3 file on the box. https://projecthub.arduino.cc/andrea3110/arduino-juke-box-42755f

Another project I found to be cool was a custom midi controller project. It is able to be used with TAL-U-NO-LX software. It uses a ton of sliders and has almost 750 lines of code! It’s almost like an analog synth where each slider controls a different sound and part of the synth sound. https://projecthub.arduino.cc/Waltter1/custom-midi-controller-4434f6