Holy s... it's hard to match leds to music

[gfvalvo]

@StefanL38

But how long does it take to transfer the data from the microcontroller into the LED-string?

Like I said:

@gfvalvo

The speed is likely limited by the required LED data transfer protocol, not the processor's speed.

It's covered in the Datasheet. The processor will NEVER be the speed-limiting factor in this transfer.