Scene summary
Cassio pays musicians to greet the general at dawn, and a clown dismisses them with wit and money. Cassio sends the clown to ask Emilia for an interview and, when Iago arrives, asks him for access to Desdemona; Iago promises to draw Othello away to give them room to talk. Emilia arrives, says that Desdemona is already defending Cassio, and takes him to a place where he can speak with her alone.
Through Emilia, Cassio asks Desdemona for a private audience.
Analysis
Cassio follows the advice Iago gave him the night before and, instead of going to Othello, seeks out Desdemona. He trusts Iago so far as to call him "so honest and so gentle" and to accept the promise that Iago will draw the Moor away to give Cassio "more freedom". Emilia reinforces the hope: Othello rejected him out of obligation, but holds him in esteem. Cassio acts in good faith, and it is good faith that Iago is going to use.