Like every Haggadah, this one contains more songs than can be sung at a Seder.  Traditionally, the most important are the Hallel psalms that were sung in the Temple, expressing awe of God and gratitude for his kindness.  Several of the many Passover songs composed in the 19 centuries since the destruction of the Temple are included, too, along with the Song of the Marsh, the oldest song in the Hebrew Bible, that our ancestors sang in joy and relief when Pharaoh’s army, intent on murder, was drowned.