Find the style by hearing a different melody is not a good way to know the end result, which is playing your song. If you want to do this, instead hearing a random melody, the process of loading, and eventually find the style you want, is harder. If we are speaking efficiency, assign the shortcut to anything else that wont speed speed the proccess of load the style is not efficient.

You can look it the other way around, instead of being forced to go through the ok button to load the style you can use the play preview button and assign double click to load style so you are able to hear the style with your own song.