What takes place in the exposition of a sonata?

tensions rises, and some sort of crisis occurs and reaches its climax (development). Then the crisis is resolved (recapitulation). Maybe there's a twist at the end (coda). The mains “scenes” within sonata-allegro form are 1) exposition, 2) development, and 3) recapitulation.

earliest

neumes above text

neumes

colored lines

neumes

4-line staff

f, c, or g clef

notes on 5-line staff with clef

mensuration (longas and breves)

time signature (perfect or half circle)

most recent

notes on 5-line staff

modern clefs

modern note values (whole, half, quarter, and so on)

modern time signature

italian words and abbreviations for dynamics and tempo

staccato, slurs, and so on