Sound Sensitive LED Strip Troubleshooting

12v lithium battery powering LED strip triggered by a small sound sensor.
Too many variables for me to isolate the problem, hoping someone can point me in the right direction.

Brand noob.
Based project on YouTube tutorial.
Only substantial difference is my LED strip is only white while his is RGB.
I don’t know how to program, but the code seems simple enough.

Sensor is calibrated so that second light on board lights when there is sound. This should trigger the LED strip but does not.

I found that if I hold a screwdriver touching both BASE and COLLECTOR of transistor, the strip lights up.

Thanks in advance.

Screen shot 2017-11-11 at 1.11.09 AM.png

Screen shot 2017-11-11 at 1.11.09 AM.png

Its hard to tell without a proper schematic, but I can't see a common ground between the Arduino and the breadboard.

That transistor will blow. It's too small. Get a MOSFET such as stp16nf06l.

Wow, the ground did the trick.
First experience w arduino forum a simple and sweeping success, thank you.
Will look into buying a beefier transistor.