Music Unlimited typically costs $7.99/month for Prime subscribers and $9.99/month for those without Prime. A Prime Student membership is half the price of a regular Prime subscription at $6.49/month, so adding the Music Unlimited plan on top would run you $7.48/month. You can stream the service's 50 million tunes, stations and playlists through Alexa devices, and the Amazon Music App and website. It's maybe worth considering if you have an Echo speaker in your dorm room.
Amazon isn't the only company that offers students a discount on music streaming though. Spotify and Apple Music each charge students $5/month. Premium plans for Pandora, Deezer, Tidal and YouTube Music cost students the same monthly fee. Those are cheaper than Amazon's deal overall, and Spotify's student plan also has Hulu and Showtime memberships. However, Amazon's Prime Student and Music Unlimited package of course includes Prime Video access and other Prime benefits, which are worth bearing in mind.