She sings rather unmelodiously.    From Wordnet, Princeton University. 

Kinnison studied the thing briefly, whistling unmelodiously through his teeth.    From Wordnik.com.  [Children of the Lens]

They approached the rest singing in chorus, not unmelodiously, but with very little variation in notes.    From Wordnik.com.  [Journals of Travels in Assam, Burma, Bhootan, Afghanistan and the Neighbouring Countries] Reference

I could hear the rain viciously swishing against the window-panes and gurgling unmelodiously through the gutters and from the pipes, but She whom I desired came not to keep me company.    From Wordnik.com.  [Drolls From Shadowland] Reference

The birds, exhilarated by the sparkle in the air, sang with a rollicking abandonment quite contagious: the very kids and goats on the crags above the road caught the infection and frisked about, tinkling their bells and joining most unmelodiously in the song; while Barney, crossing the creek upon a flatboat, lifted up a tuneful voice in the chorus.    From Wordnik.com.  [Lippincott's Magazine of Popular Literature and Science Volume 26, September, 1880] Reference

He laughed unmelodiously, and then there was a long silence.    From Wordnik.com.  [The Emancipated] Reference

It was so precisely the tone of a stage clock -- high and pretentious, and with a disturbing suggestion of being unmelodiously flawed.    From Wordnik.com.  [The Jervaise Comedy] Reference

Landwards, unrelieved me a residuum of rambotan a uncouthness amok, diaeresis the ice, and i hypothalamically unaddressed unmelodiously.    From Wordnik.com.  [Rational Review] Reference

Unwontedly, i did not house in orlando it was a burbly jet cognisance and misrule it was longitudinally a doubtfully unmelodiously slapstick.    From Wordnik.com.  [Rational Review] Reference

He sat glowering at life, as if it were just endurable at dinner time, until four of his fellows began to sing, most unmelodiously, a part song.    From Wordnik.com.  [The Letters of Charles Dickens Vol. 2 (of 3), 1857-1870] Reference

Whereas Six accumulates apparatuses, a series of "Cuckoos" rigged to sluggish metronomes are presented without their clock armature, function, or punctual song (instead the metronome arms unmelodiously open and shut their beaks and wings).    From Wordnik.com.  [artforum.com] Reference

(Not unmelodiously, I hope).    From Wordnik.com.  [Punch, or the London Charivari, Vol. 158, 1920-01-28] Reference

Nor unmelodiously; for from their throats.    From Wordnik.com.  [Knickerbocker, or New-York Monthly Magazine, March 1844 Volume 23, Number 3] Reference