Can I pay just for one month only

Yes. You can subscribe to Apple Music for as long or as short as you want. If you want to only subscribe for one month, subscribe and cancel more than 24 hours before the end of the month.

Do note, that any songs or albums you download while subscribed will stop playing and be removed when you cancel the subscription.

Yes; at least 24 hours before the payment period ends, click here and follow the instructions.

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