It totally is a simplification but its a framework that works. Birds making the sound are still an "artist", or specifically from a cognitive science perspective, an agent that produces or modifies the stimulus.

Those artists using random sounds are still an agent putting intention into a stimulus through its presentation.

There doesn't need to be a separation between "artist" and "audience" either. By observing a stimulus, you yourself modify the perception of the stimulus through a psychological phenomena known as predictive processing.

One of my research areas is in music psychology, just my 2 cents. Definitely an interesting discussion