Antonyms for the phrase "sang the praises of" could include words such as criticized, denounced, demeaned, belittled, or condemned. Rather than expressing admiration or approval, antonyms for this phrase suggest a negative opinion or an expression of disapproval. Other possible antonyms might be words like vilified, disparaged, censured, or castigated, all of which convey a sense of strong criticism or condemnation. Overall, antonyms for "sang the praises of" imply a negative or disapproving attitude, and are used to express the opposite of admiration or appreciation.