When something is growing louder or more intense, it is going through a crescendo (from an Italian word meaning “growing”). Traditionalists object to its use when you mean “climax.” A crescendo of cheers by an enthusiastic audience grows until it reaches a climax, or peak. “Crescendo” as a verb is common, but also disapproved by many authorities. Instead of “the orchestra crescendos,” write “the orchestra plays a crescendo.”
Are some people really upset by this usage? Yes, indeed.