https://wccftech.com/google-clock-gets-spotify-integration-for-custom-alarms/

Before Android phones were a thing, custom alarms were reasonably easy to set up on the erstwhile popular Nokia S40/S60-powered devices. Today, we have to be content with royalty-free music scraped off the hard disk of some Soundcloud artist. I’d much rather wake up to some epic Viking Metal as opposed to some generic 4/4 elevator music. Thankfully, now it is possible thanks to Google Clock’s integration with Spotify. According to Google’s Blog Post:

Starting today, you’ll be able to wake up to your favorite music on Spotify with the Google Clock app. Swap out the classic alarm sounds for your favorite pump-up song, a calming soundtrack or a mood-boosting melody.