Hi,
The leds are called RGB leds, but there two kind of them, the first one are powered by 12 or 24 Volts but you cannot change the color of each RGB led individually. The second ones are addressable an you can change the color individually, the most common is the WS2816b, they use some kind on proprietary serial communication, most like a shift register to store in an internal register the color of each led , 8 bits per color per RGB led (total 24 bits), but you can transmit at max 800kbps then there will be a limit in the size of the strip that will depend on the required frame rate and the memory available in the MCU used, but with a common MCU you can manage many of them.
As example, I have an esp8266 module with the NodeLua firmware installed, I read in some place that you can manage up to 250 of such RGB leds at 20 fps,with 60 LEDs per meter you can control about 4 meters or with 30 leds per meter you can control about 8 meters, but of course we also need to get the memory requirement.
Each LED require 3 bytes (24 bits) then the memory requirement is about 750 bytes to store the individual color of each RGB led.
With respect to the control I need to study the options to play the mp3 and play the RGB sequence.
Share more details of your requirements and what you initially thought about the system.