My take on this is, you're watching a movie that takes place in the winter. Wintry music is playing. All of a sudden the "cold" music along with the scene of an icy blizzard gives you a slight chilly sensation.
Afterwards you go outside and it's a blazing hot summer day. You put on the soundtrack to the movie but in this case, it doesn't make you feel any cooler. Or conversely it's freezing cold outside, but even so the wintry music doesn't actually make you feel any colder than you already do.
In the situations described above, the music was able to affect your imagined perceptions, not your real ones.
Afterwards you go outside and it's a blazing hot summer day. You put on the soundtrack to the movie but in this case, it doesn't make you feel any cooler. Or conversely it's freezing cold outside, but even so the wintry music doesn't actually make you feel any colder than you already do.
In the situations described above, the music was able to affect your imagined perceptions, not your real ones.