To use the feature, you'll just have to Shazam a song like you normally would. Once the app recognizes what you're listening to, tap the share button. As long as your apps are up to date, Instagram should appear in the list of apps that you can share the song through. Once you choose Instagram, Shazam will share the song information and album art to your story. A button that says "More on Shazam" will accompany the post. When tapped, it will take you to the song page in the Shazam app.
The integration will first be available to iOS users -- fitting, seeing as Apple just completed its $400 million acquisition of Shazam earlier this year. You'll need to download the latest update to Shazam and to Instagram to share to your Story. The feature will be coming to Android in the near future, but no specific date has been given. Support for Shazam on Instagram comes hot on the heels of the Faebook-owned app adding SoundCloud integration and support for Spotfiy earlier this year.