Synonyms of out-of-key

1 Syllable
hard, bleak, sharp, sour, harsh, flat, grim, rough, dry
2 Syllables
coarse, craggy, rusty, grating, jagged, rugged, harshest, clashing, glaring, harsher, rasping, raspy, rigid, squawky, cracked, strident, acrid, jarring, scratchy, hoarse, raucous, noisy, creaking, bitter, croaking, jangling, off-key, screeching, scratchier
3 Syllables
asperous, disturbing, unlevel, guttural, disagreeing, uneven, stridulous, severe, tuneless, astringent, earsplitting, dissonant, out-of-tune, discordant
4 Syllables
unrelenting, unmusical, cacophonous, caterwauling, unmelodious
5 Syllables
incompatible