Classroom time is limited, so the priority question in teaching pronunciation is to find an effective sequence of presentation. This article recounts one teacher's path to learning about different approaches to teaching English rhythm and why it is important. For many years, a common way of distinguishing languages has been based on the assumption of an equal length of time between stresses (stress-timed) or between syllables (syllable-timed). But the conclusions in this article are founded on a different concept, not mechanically based but meaning based. That is, instead of being based on regular time intervals, the English system works to make the speaker's intentions clear by adapting the rhythm to focus attention on certain key words. These words are the peaks of information, and it is crucial that the listener catch the signals of these peaks. Because this main signal is made primarily by lengthening the vowel of the primary stress of the important words, and contrastively shortening others, the rhythm is necessarily irregular. Furthermore, this contrastive system affects all of the other sounds, changing or even deleting them. That makes the English system of rhythm a crucial key to clarity, in both speaking and hearing effectively.