absonant
atonal
cacophonous
conflicting
cracked
diaphonic
discordant
discrepant
disharmonic
disharmonious
dissonant
flat
grating
harsh
immelodious
incompatible
incongruent
incongruous
inconsistent
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
unmusical
untunable
untuned
untuneful