Chords are usually played in a repeating sequence called a chord progression. A chord progression may repeat every 2, 4, 8, 12 or 16 bars. This could mean that the progression is repeated many times within a verse (as in many popular songs), or that the chord progression may be the same length as the verse. Once again, the best way to learn about chords and chord progressions is to learn a bit of basic guitar or keyboard. On the recording of the pieces in this book, the flute plays the melody and is accompanied by chords played by guitar and/or keyboard. The bass plays a line which is made up of notes from the particular key the song is and helps to outline the chords with these notes. The drums lay down the rhythm as well as adding drive and drama to the songs. Drum parts are made up of notes of various values (quarter notes, eighth notes, triplets, etc). Put all these parts together and you have the three basic elements of music - melody, harmony and rhythm.