Using arduino for sound and lights

Using Arduino LEDs and Multiplexing
1

Hi Guys, im new to all this and would like your help on a project im working on. The idea here is to turn on a strip of lights and then activating a piece of music with another set of leds to fade up to its maximum untill the music stops then the lights fade back down and then switches off. Then the strip that first came on fades down and switches off aswel. This will have a motion sensor to activate it all. I hope i explained it properly.

so in context:

strip light comes on (white only)
sound plays 4 secs
8x leds fade up to maximum
sound plays for about 30 sec
8x leds fade down again to minimum
play sound for 4 secs
shut down all lights

2

Have a look at the Adafruit website.
They have leds, ledstrips, mp3 shields and so on.
Like these:

3

The idea here is to turn on a strip of lights and then activating a piece of music with another set of leds to fade up to its maximum untill the music stops

That would require that you knew the length of the music because you can only get so bright with an LED. Or it would be that after a fixed time the light does not get any brighter.

What sort of sound? Does the quality of it matter?