Most flash is obnoxious and few visitors will sit through it. You be the judge. Maybe this is something that should be on your 'page of really wild stuff I can do'. Java scripts, animation. Java scripts take forever to load.
Animation can add to a page if it is used carefully.
You shouldn't put more than one moving object on a page. It is too distracting and your client may click away before he has read your message. Good pages with good content don't need music. The wrong kind of music can annoy your visitor. You have no way of knowing if everyone who visits likes your particular brand of music.