Can the technical equipment play music? Is it possible to diagnose their operation using melodies played on various machines? Is it even possible to describe music in the language of mathematics? After conducting experiments, answers to all questions were found. To achieve the goal of the scientific work – modelling and analytical description of the dependence of the pitch sound of the working equipment on the speed of its operation – a number of search and research tasks were set and implemented. These dependencies were then used to identify musical notes. Based on this, musical compositions were created using technological equipment. The ultimate purpose of this new approach was to enable equipment diagnostics based on sound analysis which it generates. The work proved the feasibility of using the graph-analytical method to search for a correspondence between the speed of operation of CNC equipment and the note it produces. The presented method found all possible notes produced by the researched CNC equipment in the operating speed range. Calculations were automated in Microsoft Excel software. We applied our note search method to various CNC technological equipment. During the performance of our research work, a malfunction of one of the CNC-machines was detected. This malfunction was successfully eliminated by using developed method. Thus, the possibility of sound diagnostics of technological equipment was confirmed.