making of LED music box interact with music part3

I start to work out a better brighter circuit and change it to a parallel circuit and link up more LEDs.

I tried 4 leds first and found that it is not bright enough and start to change the whole wiring.

Putting 2 LEDs together as a unit and make the wires more tidy.

close up

It works well

After so much soldering my brand new soldering iron change color…..wonder why it became blue