Receiving Music on an Arduino Uno

What equipment would I need for this

The Arduino does not make a very good audio processor. It can, barely, with the aid of a Fast Fourier Transform (FFT) determine a spectrum of input frequencies. If that is what you want to use to determine which LEDs to light up, then some research along those lines is in your future.

If you have some different idea about what "in sync with some music" means, you need to spell them out.