To hear a MIDI file of this beautiful song click here:
Wonderful lullaby written by Colombian composer Jaime León (1921) who set to music the poem by Eduardo Carranza. A must have song!.
At the Mundo Arts site you can find a file with the translation of the poem to English, an IPA transcription of the poem as well as an Mp3 with the poem recited by a native speaker. You can also find two comprehensive books with complet works by Jaime León.
To read a review at the Journal of Singing please click here.