I would like to ask if Arduino Uno would be okay for this project or should I use the Arduino 101 board?
I would need to detect notes being played from the violin.
I've never used the 101, but it appears to use a more powerful processor and for DSP (digital signal processing) it's nice to have all of the processing power you can get! Do you need a stand-alone device? If not, a regular computer which already has a soundcard, a display, and more processing power, might be a better way to go.
This is tricky stuff but I don't know if a violin is harder than a guitar. A guitar tuner only has to find the 6 open-string notes. Detecting all-possible notes is more difficult, if the note is not sustained it gets more difficult, and chords are even more difficult.
I did consider using RPi but then again I have 0 experience in python