OK... make your project clearer. Presumably you want to synchronise fader movements to an audio playback..
Does the audio source have a timecode embedded in it ? Like the old SMPTE track of a muti-track tape machine?
If so you have to find what that code is and synchronise to it. There's nothing magic about SMPTE. Look it up!
If not you have to synchronise your audio playback and fader movements - perhaps by starting them together and doing your own timing within the arduino. And for editing, go to a pre-defined point eg 34.45 seconds into the track .... not so easy if the audio and timing are disconnected, as you may have to go back to the beginning to get the sychronisation accurate - pain in the neck if a CD stream, much easier if it's a file. That's eg a PC job - no arduino can handle files that big. Arguably the whole job would be better handled with a PC rather than involve an arduino. I bet there are applications you can buy to do this.
What is your audio source? can you go back/ forward a specific time? To a specific point?
Allan