can't carry a tune in a bucket

An American idiomatic expression meaning someone is completely unable to sing — they are so tone-deaf or vocally inept that even the most charitable listener would struggle to call what they produce music. The humor lies in the absurdist image of carrying a tune like a physical object and still failing. Typically used in a teasing, affectionate, or blunt way to describe someone's singing without pulling punches. Common in everyday American speech and not considered offensive.

An idiomatic American expression meaning someone sings very badly, so badly they could not manage to keep a melody contained even in something as solid as a bucket. A hyperbolic and colorful way to describe someone as tone-deaf or musically hopeless. Used in affectionate teasing as often as genuine criticism. The bucket image turns an abstract deficiency into a delightfully concrete absurdity.

(idiomatic, slang) Sings very badly.