Father Christmas was generous to me this year as I was given a NeoPixel 144 LED strip which even comes an interface for controlling each of the LEDs on the device. I recently decided that I wanted to hack together some kind of music equalizer with my Raspberry Pi, just so that I could create some neat illuminations in my room while listening to music. Given that I listen to music through Spotify, I realized quickly that it would be close to impossible to retrieve the data from the music that I was listening to in real time. The second (and most important problem) is that I noticed there was no Spotify desktop client for the Raspberry Pi. Admittedly it would be possible to make use of the web client, but it still comes with the problem as to whether or not there is sufficient RAM to support such an intensive application.
I decided that the best possible method of achieving this would be to make use of the microphone port on a super cheap adapter for the Raspberry Pi. With the usage of Virtual Audio Cables, I could redirect the sound from the host machine to the microphone port and then transmit that over to the RPi's microphone port so that it could detect the music.
From there, it would be a simple case of just adjusting the lights based on the audio levels from the microphone.