sound off

(verb) express one's opinion openly and without fear or hesitation. Synonyms: opine, speak up, speak out, animadvert, sound off. Example: "John spoke up at the meeting."

(verb) start playing. Synonyms: sound off, strike up. Example: "The musicians struck up a tune."

(verb) express complaints, discontent, displeasure, or unhappiness. Synonyms: complain, kick, plain, sound off, quetch, kvetch. Examples: "My mother complains all day." "She has a lot to kick about."