In "Star Wars", was there any rhyme or reason to what R2-D2 'said', or was it just random?

Answer 1

I think that there were "phrases" that were used for general "moods" R2D2 was supposed to be in. There was a particular little chirpy, whistle-y melody that was almost always used to signify "happy" R2, and a rapid series of beeps that seemed to indicate stressed out or excited R2.

Answer 2

well if i told ya they recorded songs of humpback whales to create those sounds would it help?