Synonyms and related words :
absonant, atonal, cacophonous, cracked, diaphonic, disconsonant, discordant, disharmonic, disharmonious, dissonant, flat, grating, harsh, immelodious, inharmonic, inharmonious, musicless, nonmelodious, off, off-key, off-tone, out of pitch, out of tone, out of tune, raucous, sharp, shrill, sour, strident, tuneless, unharmonious, unmelodious, untunable, untuned, untuneful