Picaxe08m to drive a led to the music?

What i what to know is. Could i connect the positive line of a amp to one of the readabc pins of the micro. then pwnout that value on a pin. Then have a led on said pin that variys in brightness depending on the music. 1. If i could do that would the picaxe run fast enough to update the led very quickly? 2. Then could mix multiple colored leds together to have a left and right channel system?