A standard progression uses the I, IV, and V chords of a key. In the blues, these are almost always played as dominant 7th chords (e.g., A7, D7, E7) to provide that signature "tension".
Repeat the statement, often with a slight variation. A standard progression uses the I, IV, and V chords of a key
The statement (e.g., "Woke up this morning, had the blues all 'round my head.") A standard progression uses the I