Look at the attached picture for details. I used a combination of:



The RGB LED strip tutorial from Adafruit



The MSGEQ7 tutorial from skoba



I also attached my Fritzing file if you want to look at it.

EDIT: I made a small error in the Fritzing file. Please see the following comment (thank you Isaack19 for the clarification)

IMPORTANT: MAKE SURE PORT 2 (and any other ports that need to be grounded) ON YOUR MSGEQ7 IS NOT GROUNDED TO THE SAME GROUND AS YOUR MOSFETS. The Fritzing file shows the MSGEQ7 sharing ground with the MOSFET transistors. I was about to return my MSGEQ7 back from where I got it because of this. I almost gave up, but then I noticed in the serial monitor that when the 12v 5a power supply is plugged into the Arduino, the last two of seven frequencies spike up (it went from 0 0 0 0 0 4 19 to 0 0 0 0 0 8 39. Notice the last two numbers were also spiking up without the power supply plugged in.) Anyways, after grounding the MSGQE7 and the MOSFET transistors to separate grounds, all seven frequencies were at 0. I just wanted to share this with you because I saw some other people having problems.