This chapter explains a frequency-based approach to teaching vocabulary to intermediate and upper-intermediate English learners. To progress to advanced proficiency levels, such learners must find ways to engage with abundant, high-quality English input that exposes them to new, level-appropriate vocabulary learning. A frequency analysis justifies using a well-selected authentic textbook for a university course aimed at helping students contextually and intentionally learn abundant academic and mid-frequency words. Throughout the course, they read and listen to the expressive 15-hour narration of the 413-page non-fiction text by its author, who explains the principles of effective everyday living in a passionate but sophisticated tone. Since the text includes a large proportion of high-frequency, academic, and mid-frequency words, students with adequate mastery of the first 4000-word vocabulary frequency bands will have knowledge that covers 97% of the words in the text, bringing it well across the threshold for minimal comprehension and nearing the 98% threshold for ideal comprehension. Nevertheless, as the book was written for native speakers and not language learners, its low-frequency words may result in a discouraging learning burden for some of them. To lessen this burden, chapter summaries and audio explanations were created and provided in Japanese via useful tools in an Internet learning management system. This integrated course framework enriched students’ vocabulary learning, empowering them to engage confidently with complex, authentic texts. It helped them bridge the gap between their current proficiency and the demands of advanced-level English.