Pull out all the stops

The phrase "pull out all the stops" means to make every possible effort or to use every available resource in order to achieve a goal or accomplish something. It is often used to convey the idea of giving maximum effort or going to extreme measures to achieve a desired outcome. The phrase originated from pipe organs, where "stops" are the knobs or levers that control the flow of air to different sets of pipes, and pulling out all the stops would allow the organ to produce its loudest and most powerful sound.