Overview

notation of rhythm is based on using note shapes to indicate duration.
noteheads, stems, hooks, and beams are used to differentiate durations.
meter (time signature) is used to indicate repeating patterns of beats.
in hindsight, maybe it would have been better to base rhythmic notation on beat within measure.
in order to read rhythms effectively, we rely on pattern recognition.
most musicians are unaware of the extent to which these patterns make sight-reading possible.
learning about these patterns can make you a better reader.
learning about these patterns is also key to writing readable music.
there is far more to say about rhythm than what I will cover here.
getting really good at reading rhythms requires much practice.
still, I think most musicians - even relatively experienced ones - will learn something valuable here.