tuneless

From tune +‎ -less.

tuneless (comparative more tuneless, superlative most tuneless)

1. Having no pleasing tune; not tuneful.
   • 1982 August 14, Mary Ann Peacott, Liz Nania, “BT's In Boston”, in Gay Community News, volume 10, number 5, page 12:

     They insist they aren't a hardcore band, but their hectic pace and tuneless vocals are certainly in the hardcore vein.

2. Silent or mute.

• tunelessly

• unsteels