Now Playing is a feature that lets you automatically identify songs playing around you without the need to upload a sample (on Pixel 2 & above) as with Shazam. However, there was no initial way to view a history of the songs identified until the Pixel 3’s Now Playing History.
The built-in history feature, previously exclusive to the Pixel 3, lists songs by date and time. When viewing the history users could tap a song to get options to listen to it on YouTube, Play Music, or YouTube Music.
Now, Google begins rolling out the feature to the Google Pixel 2 and Pixel 2 XL via an update (version 1.0.215774583 and above). To use the feature you need to install Pixel Ambient Services.
To activate or access the Now Playing History, go to Settings > Sound > Now Playing and you should see a new section. Use the toggle to enable or disable the feature.
UPDATE: Users on Reddit continue to announce their excitement over the Now Playing feature that has finally arrived on their Pixel 2 and Pixel 2 XL smartphones.