Male equivalent of "maid", please?

Solution 1:

Actually, "lad" would be fine to change gender.
The original title, La fille aux cheveux de lin, more than suggests that it is about a "girl". "Maid" was, for whatever reason, the word chosen for the English title by a publisher.
Of course, if one is free to change the gender of the subject , then one would also be free to change the character of the subject.

Solution 2:

I would suggest the Youth with the Flaxen Hair as the title of your transposed and transgendered Debussy piece. A youth in the singular evokes the same era as maid and has the same connotation of romance.

Lad would be fine were it not for various modern associations: "Jack the lad," "He's a bit of a lad," "lads and ladettes."