Music
It is a fairly easy matter to play music on your web page. When someone views your page, their computer's sound system will start playing the music or other sound effects that you specified. In almost all cases I advise against this. The main reason is that your visitor's taste in music is unlikely to be the same as yours. A classical music lover is not going to enjoy a track from the latest Nine Inch Nails release, nor will a heavy metal fan get much enjoyment from your favorite Verdi aria. Other potential problems are that the user may be already listening to something else on the radio, or maybe the baby is asleep - who knows?
There are a few exceptions, of course. For example, if your web site is devoted to a specific musical group or composer then playing some of their music makes sense. Generally, however, I suggest that you stay away from playing music automatically on your web page. Let the user select the music if they want to hear it. Be aware that copyright issues exists also, and playing music on your site may constitute a copyright infringement.
Animations
Animated icons, scrolling text, and other moving elements are all the rage. Having some movement on your web page can indeed be an effective way to call attention to certain elements and to simply liven things up a bit. Remember, however, that more is not always better. I have seen web pages that are a seething mass of animation with the site's information (if there is any) hard to spot amidst all the squirming and wiggling. My personal preference is to avoid animation altogether, but if you want to use animation, do so sparingly. Rule of thumb: do not have more than 2 or 3 animations in view at any one time.