Mechanochemistry is gaining considerable popularity throughout the world.More and more groups join thefield and the number of reports on successful "dry and green" synthesis is growing exponentially with time.Incontrast to the impressive increase in the number of products that can now be produced by mechanical treatment,including at large scale,our understanding of the processes underlying these successful syntheses is changingonly very slowly.One of the issues that is only rarely addressed is the pulse character of mechanical treatment.With variation in the period of mechanical action(usually short and very short) there is an associated change inthe period between the pulses,during which the system can either relax,react,or both simultaneously.Thereis considerable controversy as to when the main "chemical events" occur – during treatment itself,or betweenthe pulses.In the present contribution we illustrate several examples of very different reactions(ranging fromsynthesis of pharmaceutical cocrystals to fermentative hydrolysis of the cellulose) that offer a solution to thisproblem,employing model devices with strict control over energy,duration and frequency of mechanical pulses.The result,perhaps surprising,is that for many processes the most efficient treatment is that with pulses rareenough to allow the chemical transformation to happen before the subsequent mechanical pulse.Like in music,the importance of pauses and their correct duration cannot be overestimated.