Sometimes a song does not begin on the first beat of a bar. Any notes which come before the first full bar are called lead-in notes (or pick-up notes). When lead-in notes are used, the last bar is also incomplete. The notes in the first and last bar add up to one full bar. When playing songs with a lead-in, do not press the chord key until the first beat of the first full bar.
This song is an early Jazz standard made popular by brass bands in New Orleans. It contains both quarter and half rests.