The 12 Bar Blues is a pattern of chords which repeats every 12 bars. There are hundreds of well known songs based on this chord progression, i.e., they contain basically the same chords in the same order. The 12 Bar Blues forms the foundation of Blues music, and is also commonly used in Rock music.
The following 12 Bar Blues is in the key of C major, and uses some of the chords you have learned so far. When a song is said to be in the key of C major, it means that the most important chord (and usually the first chord) is the C chord.
To finish a 12 Bar Blues, press the ending button, or play one bar of the opening chord (in this case a C chord), and press the stop button.
This pattern of chords will probably sound familiar to you.
This is a flat sign. When a flat sign is placed before a note on the staff, it means that you play the key immediately to its left. This key may be either black or white. The note B flat (written as Bb ) is a black key. It is shown on the staff above.
To play the note Bb, play the black key immediately to the left of the B note (white note), as shown on the diagram.
This 12 Bar Blues in the key of C makes use of the note Bb.