Is this possible?
Maybe.
You need to add a lot more details, though.
using a knob (that can stop, rewind, and fast forward the songs)
The knobs in my house are connected to drawers, and are used to open and close them. Most of them are wood. One is ceramic. I haven't a clue how you could use them to stop, rewind, or fast-forward songs.
Assuming you meant potentiometer, but couldn't spell such a long word, you need to define what potentiometer reading, or range of readings, should start the music, what reading, or range of readings, should rewind, and what reading, or range of readings, should fast-forward the songs.
You need to explain what is going to be playing the song. By itself, the Arduino isn't.
and the music controls the playback of the video.
"controls" is so vague as to be meaningless. What is playing the video, and how is the music going to stop, rewind, or fast-forward the video?