Which software to use

I have a project I am trying to expand. Currently I have Flash CS4 controlling 12 LEDs in time with an MP3 file. Due to the cost of CS4 I want to switch to another programm, vb, c+, processing.

I would also like to use shift reg to expand the number of LEDs. I would then need to send the data to Arduino to shift out. I could not get this to work with CS4 could only controll pins and not send data. Any thoughts on what software would be best to work with?

How do you get the "time" (beat / rythm whatever) from the MP3 ?

Any programming environment that can read/write to/from a serial port can send data to Arduino.

In flash CS4 it was easy to get the timing. That is why I used it first. Flash is designed with a timeline type of approach. You can import any mp3 and it will show its spectrum in the layer it is imported. Then add layers under to turn on and off the LEDs when you want them to. Will get a picture of the program to show this better tonight.

Or if anyone knows how to send data to the arduino from CS4 this will work for me too. Not just the pin output or input. Need to send a number to it (0-255) then shift it out with arduino to the shift reg.

picture of CS4 program

You might look into Python, PyGame, and SDL:

http://www.python.org/ http://www.pygame.org/ http://www.libsdl.org/

PyGame is built on Python and SDL, BTW...