Hi Maya,
I'm no neurologist but it sounds like you might be having audio seizures and that's when certain sounds can trigger a seizure for a person. If I may ask when you are playing this music or watching it are there a lot of bright flashing lights or strobe lights? If there is it could be the lights that are triggering the seizures this is known as being photosensitive to certain colors.
My advice to you is to start keeping track of any of your possible seizures by getting a calendar and write down what time of day/night you have these seizures with a discription. If you have a monthly cycle circle the date when you start and stop your period because it can be hormone related.
The best thing for you to do is to see a neurologist at an Epilepsy Center which are usually found at University Hospitals. I've gotten the most help there or you can see an Epileptologist - Dr. specializing in Epilepsy who will want to run some tests on you. I will tell you that using nutra sweet and cell phones can trigger seizures because they cause more electrical activity in the brain as well and eating to many sweets and starch foods.
The reason why your arms are jerking around is because it's a motor type of seizure causing your body to move around without control. That's the reason why you you have the eye movement also. As far as the laughing it sounds like the seizure might be starting in the Right temporal lobe since that's the area of the brain that shows emotions and the same area where music is. Try taking vitamin B12 1000 mcg. a day and see if that helps until you see a neurologist or epileptologist. Here's wishing You Well and May God Bless You!

Sue