The union of music and film has a long and tangled history that rivals any of the fabled romances that have graced the silver screen. Sometimes conjuring moments of fear, sadness or dread and other times creating a instances of pure majesty and joy, music is always a powerful aspect of the movie-watching experience.

While they're often rivals as distinct industries in the entertainment universe, music and movies can be a formidable combination when united on celluloid. From the first notes Al Jolson sang in "The Jazz Singer" in 1927, ushering in the era of sound motion pictures, the creative lights of the movie industry have adopted music as a device to serve a film's ends.

Whether it's through the use of popular songs, classical symphonies or abstract soundscapes, music on film can set a mood, further a plot point without using dialogue or just to help sell the flick to suspicious audiences. A hit song can neatly encapsulate the theme of the picture and in rarer instances, defines an entire era. With these wide-ranging capabilities, music has become an essential implement in any filmmaker's toolkit.

At its best, the correct music appearing at the right moment of a movie can make your hair stand on end. Music has always been capable of eliciting a powerful emotional response and when married to a series of images, the experience feels all the more meaningful and seductive. The one of the best examples of music's power to frame a movie might be the use of Richard Strauss' "Also sprach Zarathustra" during opening sequence of Stanley Kubrick's "2001: A Space Odyssey."

In the end, music helps film realize its full potential as the ultimate art form in popular culture.

Click on to see our list of the greatest marriages of movie and music, in no particular order.