Singing as the easiest form of music is, I think, one of the oldest pleasures of mankind.
The oldest notated song in Europe was found on a Greek tombstone of the 1st c A.D.. It is a four-liner of the kind skolion, i. e. a drinking song: "Show yourself as you are, and dont be dreary too much; life is short, and time will bring an early end". (St. Paul refers to this attitude in one of his letters; can't give the place, don't have my NT not with me). In every good German schoolbook you can find the picure of the stone and the transformation of the tune into modern notation.
An early medieval tune of the "Crusaders' song" by the noble German poet and singer Walther von der Vogelweide (12th c. A.D.) is also preserved; I know it by heart.
A fine collection of short Mediterranean love songs you may find in the Old Testament in the Cantica canticorum, i. e. "Songs of songs = the best songs". The German orientalist Tischendorff states that he heard the same type of songs still sung in Palestine in the middle of the 19 c. A.D. In my songbooks I find some of these biblical songs with tunes, but I can't say how old they are, traditional or written by modern composers of the last century.

Wilfried