Apple Music is.
During the signup process, you're asked if you'd like to start your free three-month trial. Part of that process is you agreeing to pay for Apple Music once your trial expires, with no further action required on your part.
Only, not everyone is going to want Apple Music to automatically renew on September 30 (or whenever your free trial is up). You can set a calendar reminder to debate whether or not you want to pay up, or you could disable auto-renew right now while you're thinking about it; here's how:
- Launch the Music app and tap on the profile icon in the top-left corner.
- Select View Apple ID.
- Under the subscriptions section, tap on Manage.
- A list of the subscriptions, past and present, connected to your Apple ID will be displayed here. Find and tap on Your Membership >Apple Music Membership.
- Tap on the Automatic Renewal button, resulting in the switch sliding to the Off position.
Should you decide during the trial period you want to keep Apple Music around, you can repeat the above process to re-enable auto-renew and let your iTunes account take care of the rest.