How to detect a droplet when hitting water surface

I want to create an generative music sculpture which is based on falling droplets as triggers for musical notes.

im currently trying to figure out how to detect a droplet falling onto the surface of water in a bowl. I basically just need to proram a switch-.... ON = droplet has been detected, OFF = nothing has happened

I know you could detect the droplet with an IR beam close to the faucet, or use photoresistors and LEDs, but I just want to figure out if it is possible to somehow turn a liquid surface into a sensor.

I think maybe this example is what i am looking for!

mvh Bjørn Dam Larsen

if you know the place where it drops you might have a laserbeam that shines just above the surface being interrupted...

or using a piezo that detect trembles(?) in the sculpture or a microphone?