If in the past Myspace had a song feature on the profile, now Instagram has started testing this feature. Simply put, it offered a way to add autoplay music to posted photos.
Instagram announced through its Creators account that the feature gives creators an additional tool to "bring their content to life and express themselves".
The same way that music has helped in Reels and Stories. It shows that music is a “important part” so this will help add the ability to combine music and images in News Feed
“Whatever format works best to tell your story, you can now add background music to your favorite photo moments to bring them to life,” says Instagram.
https://www.instagram.com/p/CkyceXnpjWT/
Simple operation as follows, select the photo to add as usual, then when sharing, select "Add music". The interface will allow users to search for songs or browse Instagram's "Trending" or "For You" lists. Once a song has been found, users can choose a clip length (between 5 and 90 seconds) and then publish the post. That selection will then play in the News Feed when other users scroll there, as long as they don't mute the sound.