When we hear music, we perceive things like pitch, timbre, duration. We don’t perceive sadness in music. Rather, certain types of music tend to cause certain types of feelings in listeners. The parts of music we do perceive are strongly bound to the music in the way the author defines. That’s how we can pick out individual instruments or have a conversation while music is playing.
Feelings are, well, more layered and do combine with those created from other perceptions. They also can last beyond the immediate perception.
Theres a great radio lab episode [1] about music, language, perceiving sound, and the connection between music and emotion. It’s such a fascinating topic.
[1] https://www.wnycstudios.org/podcasts/radiolab/episodes/91512...