Key of E and Key of F

No matter what kind of a day I am having, music seems to make it better. I appreciate a broad spectrum of genres - from Jazz to Classical, from Country to R and B, and everything in between. Pictured here is a Stevie Wonder song written in the Key of E - 4 #'s ( sharps). Go large to see the music score with the key signature.

One of my favorite classical pieces - Mozart's Eine Kleine Nachtmusik - is written in the Key of G (one sharp).

Have a listen to each of these songs, if you have a moment. I'd say there is quite a sharp contrast between these two music pieces! Not to mention the sharp contrast between the black and white piano keys, black keys being the sharps or flats.