Question

choose a word or phrase to complete each part of the summary for \lets (please) get this party started.\
djs want people to enjoy the music that they play. for this reason, they connect with the crowd by playing music that is personal to them.
djs listen and watch the crowd they can decide what music to play.
key ideas
gists
djs need to pick the right songs to keep a crowd interested.
djs play music that is personal to them as a way to connect with the crowd.
djs listen to the crowd to decide when to play the next song.
the dj communicates with the crowd and plays songs that get the crowd excited about the music.

Explanation:

For the second blank (Djs listen and watch the crowd ____ they can decide what music to play):

We need to choose a conjunction that shows the purpose or result of DJs listening and watching the crowd. "so" is used to indicate that the action of listening and watching the crowd is done in order to be able to decide what music to play. "therefore" is usually used to introduce a conclusion and is often placed at the beginning of a clause or a sentence, while here we need a conjunction to connect the two parts of the sentence in a way that shows the purpose, so "so" is more appropriate.

Answer:

so