The gain is 101 times so it should be fairly sensitive. Maybe that expensive no-name-brand mic is garbage.
What is the value of your volume control pot?
Maybe the transistor has its pins connected backwards.
Also I swapped the Chinese Purple Ultra Bright LEDs out for some UK Ultra Bright Blue ones (much brighter) 5mm BLUE, 8500mcd 3.3Vf Ifmax=25mA and when i did that they stayed on permanently??
A purple LED is almost an ultra-violet one that is invisible.
See my attachement. When there is no sound then the output to the LEDs is
ZERO VOLTS so how can the LEDs stay on permanently?
Oh. Maybe you are using a breadboard and the millions of messy long jumper wires are antennas that pickup mains hum.