Today Microsoft has introduced it's subscription music service, Xbox Music Pass on the web today. This means that subscribers or 30 day trial users can now access the service using a web browser instead of your Xbox, Windows Phone, etc.
For those who are unaware, Xbox Music Pass is a subscription service, with no ad-based free tier option like Pandora and Spotify. However, users can sign up for a 30 day trial of the service before subscribing to a subscription.