Synonyms of off-key

1 Syllable
sour, harsh, flat
2 Syllables
clinker, harshest, harsher, jarring, scratchy, deviant, squawky, off-pitch, off-tone, scratchier
3 Syllables
divergent, tuneless, abnormal, dissonant, out-of-key, out-of-tune, discordant, untuned
4 Syllables
anomalous, inharmonious, irregular, unnatural, unmelodious, unmusical