At one point, you had to own music before you could listen to it--unless you used the radio. Nowadays, the radio has evolved and merged with the Internet, which has brought us a new form of media: online radio! Or in other words, music streams. And let me tell you: streaming music is a wonderful, wonderful thing.

Online radio is picking up steam now that there’s a good bit of competition driving the technology. You might be familiar with services like Pandora and Spotify, but now that you can stream music on-the-go with your mobile device, it’s better than ever. Join me as I explore and compare the five best music streaming services available today.

Spotify

Price: Spotify Mobile is available for Free! There’s no price that’s better than that. With a Free account, you can stream millions of songs instantly, as well as play local music files and share links through social media. If you upgrade to Premium ($9.99 / month), you lose the ads and you can listen to Spotify playlists while offline.

Selection: The Spotify music selection is rather impressive. I tried searching for as many obscure artists as I could find and it had all of them. Furthermore, through their “similar artists” feature, I was able to find a ton of artists that I’d never heard before--and they fit my preferred genres perfectly. Spotify is spot on here.

Availability: Absolutely aces for availability. They have apps available for iPhone and iPad models, Android models, Symbian models, Windows Phone models, and even Blackberry models! And even if your phone isn’t supported, you can always use their mobile website interface. In terms of countries, the free version is only available in the US and large parts of Europe, though.

Interface: I don’t know what else to say except, “Awesome!” There’s nothing spectacular or unique about the Spotify interface, but it is supremely polished and sleek. I had no trouble navigating the mobile site or the Android app, and the amount of work they put into it really shows.

Last.fm

Price: Last.fm’s pricing model is a hit-or-miss kind of deal. If you live in the US, UK, or Germany, then their online radio streaming feature is entirely free. If you live elsewhere, though, then you’ll need to subscribe (€3.00 / month). Otherwise, you can listen to 30-second samples for free, but that’s about it.

Selection: Since Last.fm has been around for so long (started in 2002), I’m not surprised that they’ve built up such a huge library of songs and artists. I’m confident that if you’re looking for a certain song, Last.fm will have it in its library of songs. Excellent selection.

Availability: Last.fm as a mobile app is available on Android, iPhone, and Windows Phone. As far as I know, Last.fm as a music streaming service does not have a limitation on the countries that can subscribe.

Interface: The Last.fm app for Android is quite simplistic, perhaps overly so. You can search and browse online radio stations and listen to music just fine, but that’s about it. Nothing to complain about, but nothing to run home about, either. The fact that there’s no web-based interface is disappointing as well.

Grooveshark

Price: Listen to unlimited streaming music for free on both the web and HTML5 mobile app. Unfortunately, you’ll have to see advertisements. Not a bad trade-off, in my opinion. Upgrading to Grooveshark Anywhere ($5 / month) eliminates ads and unlocks access to the iPhone and Android apps.

Selection: Grooveshark doesn’t like to say how many songs they have in their library, but if you consider the fact that users can upload songs to the Grooveshark servers, then you’ll understand just how large a selection they have. There are tons of songs on Grooveshark. You won’t be disappointed.

Availability: Grooveshark apps are available for Android, iPhone, Blackberry, Palm, and Nokia devices, though you’ll need to be a subscriber for app access. If you’d rather not pay, you can always point your phone to their mobile website interface which is entirely free.

Interface: I’ve only used the browser-based interface for mobile devices, but I liked it. The use of HTML5 technology is well-designed and everything flowed together well. Listening is easy, and the convenience of only needing a browser can’t be ignored.

Pandora

Price: Pandora is one of the most recognized names in online radio, and for good reason. You can listen to an unlimited number of songs without paying a cent, though there are ads every once in a while. If you upgrade to Pandora One ($3.99 / month or $36 / year), you can eliminate the ads and unlock higher quality audio.

Selection: Unfortunately, as awesome as Pandora is, their musical selection is somewhat lacking. As of the start of 2012, Pandora had approximately 900,000 songs and 90,000 artists in their database. It’s good for finding the mainstream stuff, but some of the more obscure tracks will be lost.

Availability: There’s a Pandora app for the Android, iPhone, iPad, and Blackberry, as well as the Nook and Kindle Fire. Unfortunately, due to legal requirements, the Pandora service is only available for a limited number of countries.

Interface: Pandora has an interface that I’ve grown to love and adore. The fonts are clean, the design is unobtrusive, and everything is easy to find, easy to use, and easy to enjoy. One of the best music apps out there, period.

Nokia Music

Price: The Nokia Music feature is absolutely, entirely free! It won’t cost you anything, and that’s that.

Selection: Nokia’s Mix Radio is an online radio service with a twist: the playlists are devised and created by real people, not algorithms or programs. These unique playlists (over 150 of them) are compiled from over 17 million songs, but on top of that, Nokia Music will create custom playlists for you based on your tastes. Simply excellent.

Availability: The huge downside to Nokia Music is that it’s only available on Nokia Lumia 710 and Lumia 900 devices. Furthermore, it’s only available in the United States. I realize that excludes pretty much all of you (myself included), but if you are using one of those devices, you should really check this out.

Interface: The interface is okay. Since the Lumia models run on Windows Phone, that’s the kind of interface you’re getting: the Zune-like appearance with lots of whitespace and big text. Whether you like it or not is down to personal preference here.

Conclusion

My personal winner out of this list is Spotify, though Nokia Music is a close runner-up. The only reason it didn’t win the number one spot was its extremely limited availability. If it expanded to Android and iPhone, it would overtake Spotify without a doubt, in my opinion.

So there you have it. Being able to stream music on-the-go and on-demand is becoming something of a necessity in our ever-mobile world, and these services are doing their best to fill that void. What do you think? Share your comments with us!

Image Credits: Headphone Music Via Shutterstock, Nokia Music Screenshots Via AAWP