Londonderry Air is an air that originated in county Londonderry, Northern Ireland.
Here is an arrangement for Flute and guitar duet. Early Intermediate.
With tablature. With downloadable mp3 just for audio help. 
With lyrics and melody line. With finger position suggestions.
Pages: four pages score and parts (3 pages both flute and guitar, 1 page flute part), 1:55 min.