Bluetooth HC06 doesn't work on my arduino pro micro

Hi, i am new to arduino. I just bought one Arduino pro micro for my project. The code i wrote for the project worked perfectly on arduino uno, but when i transfer it to arduino pro micro, it doesn’t work at all, please help.
My project is to control the buzzer to make noise and an led to light up using bluetooth.
Sorry i couldn’t upload my project wiring picture because it is too messy to be seen clearly.
My project is powered using computer usb
pin 6 is connected to a piezo buzzer
pin 5 to a led
the RX on arduino is connected to TX on the bluetooth hc06
TX on arduino to RX on bluetooth HC06
I have attached my sketch
please help me with this.
any suggestion will be appreciated

bluetooth_4UTAR_.ino (1.05 KB)

Melody.ino (716 Bytes)

pitches.h (1.96 KB)