Interactive Circle of Fifths vs Sumizeit

Explore the Interactive Circle of Fifths.

See and hear the relationships between chords in any key.

Learn fingerings from piano and guitar visualizers.

Study major, minor, and diminished chords, pentatonic, blues, diatonic, and harmonized scales.

Sumizeit is a micro-learning app that helps you learn faster without spending hours reading. It turns the world’s best nonfiction books into clear, structured summaries you can finish in just 5–10 minutes. Each summary breaks down big ideas into bite-sized lessons, making it easy to absorb key insights anytime, anywhere.

Designed for busy minds (and especially great for people with ADHD), Sumizeit focuses on clarity, speed, and retention. Learn through short reads, audio options, and quick quizzes that reinforce what you’ve just learned. Topics range from personal finance, business, psychology, health, and productivity to science, history, and self-improvement.

Whether you want to replace doom-scrolling with something meaningful, prepare for a conversation, or steadily build knowledge every day, Sumizeit makes learning feel effortless. No fluff, no filler just the core ideas that actually matter, delivered in a format that fits real life.