Making the music sound like the text being sung is called

This is called as Word Painting. Word painting is making the music sound like the text being sung. Word Painting is also known as the Tone Painting. The word painting also shows the literal meaning of the song. In music painting it also shows the emotions and the ideas of the music. 

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