So a middle C in the bass clef, which is on the line directly above the staff, is written as a D on the treble clef's fourth line. The term "middle C" comes from the fact that this note is half way between the bottom of the bass string and the top of the treble string. It is important to remember that when you are looking at the bass clef, the notes go down five strings instead of four. So the pitch that is represented by the middle C on the bass clef is one whole step lower than a normal C. Here is a visual aid to help you find the middle C on the bass clef: Now, it is easy to see why this note is called the "middle C". It is because it is in the exact center, meaning, it is exactly halfway between the bottom of the bass string and the top of the treble string. This note can be played with your left hand only. The thumb of the left hand must touch the bottom string while the other fingers play the note in succession off the neck of the guitar.