Here is the beautiful and evocative plainchant setting of Ave Maris Stella.
Here is the Gregorian notation. This hymn is sung at Vespers of the Divine Office and the Little Office of the Blessed Virgin Mary. Its origins can be traced back to the 9th Century found in the Codex Sangallensis, a manuscript now found in the Swiss Monastery of St. Gallen. Attribution includes Venantius Fortunatus.