I had never heard or heard of "Ach Elslein" until coming across it in
Lieder, Songs und Gospels 3
This is a very old German folksong by Hans Ott (1533-1550). This is a lovely short love song of longing and pining by the singer for his beloved Elslein (little Elsie). They are separated by the ocean and our hero complains of his heartbreak and longs for the happy days of reunion.