but I don't think it will work very well (if at all) as drawn.
You were right, it does not work
Since i am in a good mood and had a blast cooking today i will be way too nice, now.
I had a bit of fun poking things in my breadboard, i gave up on the "soft start" feature, i do not know why but i could not get it to work triggered of the piezo and OpAmp. My scope was no help either, i suspect that my test rig was the fault.
I could not cobble together a rudamentary drum without going to the shed.
And it is cold and dark in the shed now and i am in my PJs allready.
Video:
Edit: You can not see it that well in the video but the circuit will respond with varying brightness to the sound level. The louder the brighter.
Schematic:
I still suspect the piezo to put out way more voltage then the circuit can handle but without a real drum i can not be shure.
The the body harmonics in the drum body are loud, very loud.
You should at least put two clamping diodes on the input, i think, i had piezos blow circuits more then once.
In the above circuit you have to replace the second BC337 (T2) with a fairly big NPN or a darlington transistor that can handle the power the LED strip requires.
The BD679 from my other schematic should work, but it depends on what you can buy.
But again i advice you, i am barely more then a monkey poking wires. But since nobody else had a suggestion i guess you are stuck with me :-P
Explanation what the circuit does:
IC1A is a non inverting amplifier to amplifiy the piezo output, there is no rectification or negative voltage protection, you should put two clamping diodes on the input but i omited them to simplifiy things.
The amplification is set by the potentiometer, the pot value is not that important, annything above 10K is good. It does not have to be a pot, two resitors will to as well but a pot gives you something to tweek.
Since the opamp can not source enough current T1 will charge the capacitor wich serves the purpose to "fade out" the led.
The LED in the circuit has no resistor, it should have one but your LED string should has them build in. Check that before powering up.
Why i choose those components and values you ask? They were in my used parts bin...