Hello, and welcome to the 7th Lesson of this series of lessons created by Team 15060. If you do not know me yet, my name is Musica. I reside at the bottom right hand corner of your browser screen. You'll get to know me pretty well, if you haven't already. You'll learn to deal with my sarcastic and unhumorous jokes, my unwitty remarks and my faithful, yet probably unsuccessful attempts to encourage you as you proceed through these lessons. But one thing you cannot deny is my ability to quickly and easily teach you music. Stick with me and I'll try to help you learn as much as you possibly can.

As you approach this lesson, you might be wonder what accidentals are. Accidentals are little alterations in the pitch or the tone of notes, either up or done. If the alteration is up so that the note sounds a little higher in pitch, it's said to be a sharp. If the alteration is a little down so the note sounds a little lower in pitch, it's said to be a flat. Well, then, what is a key signature. Well, let me show you something analogous to this term. Remember anything about time signatures from your rhythm lessons? You were introduced to time signatures briefly then (you'll get a more in-depth look at time signatures in lesson #12). They told the musician about how to divide and subdivide each measure.

The next question you might be wondering is how do flats and sharps look like? Look at the follow picture of two notes. The first one is a picture of a C sharp, the second note is a picture of a B Flat. Notice how they look. The sharp, as Lucy said in I Love Lucy, looks like a "lopsided tic-tac-toe". The flat sign looks like a lopsided lowercase b.