Using a string to register an on/off response

Hey everyone, I'm very new to Arduino so any help for this question would be greatly appreciated!Itsneed for an installation i'm designing for university. Essentially, i'm going to have a tight string thats connected from the ceiling to the ground. When you flick the string, it triggers a midi response which will play an instrument through Ableton.
I already have the Uno, but does anybody know what type of sensor i will need for this? im guessing the string itself will need to be tied to the sensor in some way.

Thanks so much!

Some kind of tension sensor like a load cell comes to mind.

Or if the string is metal, something conductive based, such as a capacitive sensor. The capacitance of the line will change drastically when touched by a person.

You can sense vibrations and pressures from hard to tiny with piezo discs, same as acoustic instrument pickup.

There is a Youtube named Ants, Amplified showing ants walking on a disc on stone amplified many magnitudes and you can hear every little detail. With less amplification like from an opamp or transistor you can detects knocks on doors.

Know your electricity or go close by a known good circuit with piezos, they make current rush in spikes that go one way when you press and the other on release. With diodes the flow can be redirected so Arduino never gets -V.