The Collaborative International Dictionary of English v.0.48:
Inharmoniousness \In`har*mo"ni*ous*ness\, n. The quality of being inharmonious; lack of harmony; discord. [1913 Webster] The inharmoniousness of a verse. --A. Tucker. [1913 Webster]WordNet (r) 3.0 (2006):
inharmoniousness n 1: a lack of harmony [syn: disharmony, inharmoniousness]