I had a leftover 741 op amp and tried to make a simple non-inverting amplifier, but the LED just stayed on the whole time.
The 741 is an old, low spec device
I then tried to make a comparator, using a variable resistor to adjust the voltage into the inverting input and the audio input into the non-inverting input, but the LED just stayed off.
Did you try to use the 741 as a comparator.?
I can't believe making an LED blink in time to sound is such a difficult task.