I hope the title in the DT is corrected. The date of the poem should be added and Yeats should be credited with adding the original tune.

In addition to Bill Kennedy's reproduction of the poem, with excellent notes, the poem as published in "The Wind Among the Reeds," 1899, also is reproduced at the Bartleby website: http://www.bartleby.com/146/9.html, Aengus Other Yeats poems at this site.
The note in the DT that "Donovan wrote a better tune" or fitted a better tune should be changed to read "Other tunes by Donovan (date) and-----." Whether a tune is better or not is in the ear of the individual performer or listener.
Numbers of pertinent threads should be added and click links posted (useful to see the thread number as well as the link). Bill Kennedy's Discography is thread 46666: Discography