Unmusical (adjective)

1. Not having a natural or appreciative feel for music.
2. Lacking in musical quality or ability.
3. Not pleasant or harmonious to the ear.

Origin:

Late 17th century, from un- + musical.

Examples:

1. The unmusical performance was off-key and out of tune.
2. The unmusical voice was shrill and grating.
3. The unmusical singing was a cause of ear pain.
4. The unmusical melody was dissonant and chaotic.
5. The unmusical person was tone-deaf and couldn't carry a tune.