Once largely available only through Pandora, Internet radio and/or on-demand music services seem to be everywhere today. With Apple likely to release their own “iRadio” service very soon, we thought now was the perfect time to update our readers on some of the services that are already available. Here are seven of the best:

Last.fm

Last.fm

Last.fm

Founded in 2002, the Last.fm service was acquired by CBS Interactive in 2007. It currently offers free music streaming via the Web for users in  the United States, United Kingdom, Germany, Canada, Ireland, Australia, New Zealand, and Brazil. Last.fm Radio is available through computer and iOS applications in the United States, United Kingdom, and Germany. This requires a subscription, which is $3 per month, or $36 per year.

Last.fm’s primary purpose is to help users build a listening history across any platform. Currently, the service integrates with over 600 of these platforms. This compatibility allows users to get personalized recommendations based on what songs others are listening to.

A subscription gives users uninterrupted radio listening, ad-free browsing and streaming, and access to the Last.fm VIP zone. Here customers can try products before they are released to the public.

Last.fm at a glance

  • Website link
  • Computer applications available for Mac, Windows, and Linux
  • Official iOS apps: Festivals (iPhone), Last.fm (iPhone), and Scrobbler for iOS (universal)
  • Tracks: 18 million and counting
  • iOS: After a free 50 track trial, Last.fm Radio on iOS devices requires a subscription
  • Combination of on demand and radio

Bottom line: The price is right, although some albums are incomplete. Plus, it sometimes takes a while for new music to arrive. Still, the company’s tour guide is second to none. Overall: B- iOS: B

Pandora

Pandora

Pandora

Pandora Internet Radio first rocked computers in 2000. Since then, when many think of streaming music, they think of this service by the Music Genome Project. Operated by Pandora Media, Inc., it is available in the U.S, Australia, and New Zealand.

Unlike other services, Pandora Radio is just that — radio. As such, users can’t select full albums to play. Instead, Pandora will create up to 100 radio stations based on your artist, genre, or composer preferences.

You can listen to unlimited music via the Web, or 40 hours per month on mobile devices. When this limit is reached, you can continuing listening via the Web for free, or pay $0.99 to do the same on the app for the rest of the month.

Pandora One is a $3.99 per month premium subscription service. With it, users can access music through a computer application, and remove ads on every platform. Additionally, Pandora One customers experience Web music in 192k bits per second format.

Pandora at a glance

  • Website link
  • Computer application available for Mac and Windows, available only to Pandora One customers
  • Official iOS app: Pandora Radio (universal)
  • Tracks: Less than 900,000 songs
  • iOS: Limited to 40 hours of music streaming per month, or $0.99 for additional time
  • Radio only

Bottom line: Compared to other solutions, Pandora Radio’s library is surprisingly small. Still, it is one of the few that offer free Internet radio on mobile devices. Overall: C+ iOS: B-

Rdio

Rdio

Rdio

Rdio was created by Skype co-founder Janus Friis in 2010. The service is currently available in 17 countries, including the United States, Australia, and Spain.

Unlike the other companies listed, Rdio doesn’t offer a long-term free service. However, new users can try the service for free for up to six months on their computers. Once the trial ends, Rdio offers two main packages: Web, and Unlimited.

Priced at $4.99 per month, Rdio Web offers unlimited music streaming via a browser, and through a computer application. Unlimited, which is $9.99 per month, adds unlimited mobile streaming to the mix. With this package users can also access music via Sonos, and Roku devices.

For $17.99 per month, Rdio may be played on two devices at the same time.

Rdio at a glance

  • Website link
  • Computer application available for Mac and Windows
  • Official iOS app: Rdio (universal)
  • Tracks: 18 million and counting
  • iOS: Must purchase $9.99 Unlimited subscription
  • Combination of on demand and radio
  • Active Unlimited subscribers can download songs to their mobile devices for offline use
  • Integrated with Twitter #music

Bottom line: Rdio includes one of the largest libraries of music available. In addition, it is typically one of the few services to offer new albums on launch day. No matter the platform, Rdio is quick, intuitive, and a dream to use. Overall: A iOS: A

Rhapsody

Rhapsody

Rhapsody

Rhapsody’s roots go back to 2001 when it was owned by RealNetworks. Since 2010, it has been a standalone company and is only available in the United States.

The service is $9.99 per month. This includes unlimited on-demand music and Internet radio across multiple platforms. Although there is no free service, a free trial is available.

Rhapsody at a glance

  • Website link
  • Computer application available for Windows only
  • Official iOS app: Rhapsody (iPhone), and Rhapsody for iPad
  • Tracks: 11 million
  • iOS: Must pay $9.99
  • Combination of 0n demand and radio

Bottom line: Smaller number of tracks compared to other services make Rhapsody less than ideal. Plus, they really need a Mac application. Overall: B- iOS: B-

Slacker Radio

Slacker Radio

Slacker Radio

Slacker Radio is an interactive Internet radio service available in the United States, and Canada. User can create and share personalized music stations, or access one of the hundreds of expert-curated music stations already available.

Calling itself the “most complete music service on Earth,” Slacker Radio first launched for the Web in 2004. Since then, the Internet music service has expanded onto mobile devices.

Even with a free account, users can listen to Slacker Radio on the iPhone/iPod touch and iPad. However, the free account includes ads and doesn’t allow the user to skip songs.

For $3.99 per month, users can upgrade to a Slacker Radio Plus account. With this, the ads go away, and you can skip songs. This package also adds ABC News and ESPN Radio to the mix. Finally, for $9.99 per month, Slacker Premium offers users a complete music streaming experience, including the ability to listen to music on demand.

Slacker Radio at a glance

  • Website link
  • Computer application available for Windows only
  • Official iOS app: Slacker Radio (universal)
  • Tracks: 13 million
  • iOS: radio is free with ads
  • Primarily radio only, but $9.99 package offers on-demand tools
  • Active Premium subscribers can download songs to their mobile devices for offline use

Bottom line: If you’re strictly looking for an Internet radio service, Slacker Radio is probably the best on the market today. Plus, it is one of the few that concentrates on providing news and sports channels too. Not available internationally though. Overall: B iOS: B+

Spotify Radio

Spotify Radio

Spotify Radio

First launched in the United States in 2011, Spotify is probably the most recognized streaming music service available today. It is also the service that seems best prepared to take on whatever service Apple is working on. Launched in Sweden in 2008, Spotify is currently available in multiple countries.

Spotify Free offers ad-supported streaming radio on a computer through a separate application. This isn’t an unlimited music service, however. Instead, there are limits on the amount a music a user may listen to each month. New users are exempt from these limits for six months.

To listen to radio on a mobile device, you must upgrade to the $4.99 Unlimited package. With this, you may stream unlimited radio across multiple platforms including iOS without ads.

The $9.99 Spotify Premium package unlocks on-demand music. Additionally, songs and albums may be downloaded for offline listening.

Spotify at a glance

  • Website link
  • Computer application available for Mac and Windows only
  • Web-based player is currently in beta
  • Official iOS app: Spotify (universal)
  • Tracks: 20 million
  • iOS: Must pay $4.99 for radio
  • Combination of 0n demand and radio
  • Active Premium subscribers can download songs to their mobile devices for offline use
  • Integrated with Twitter #music

Bottom line: Spotify, like Rdio offers an amazing streaming music experience. Rdio is slightly better thanks to a crisper user interface, and ability to run through a Web browser. Overall: A- iOS: A

Twitter #music

Twitter #music

Twitter #music

Don’t be fooled — Twitter #music isn’t a separate music service. To listen to full songs in an Internet radio format requires a Rdio or Spotify subscription. Otherwise, you’ll hear songs in 30 second snippets only courtesy of iTunes. Regardless, we’re including Twitter #music because of its potential.

Twitter #music at a glance

  • Website link
  • Web-based player available to anyone with a Twitter account
  • Official iOS app: Twitter #music (iPhone only)
  • Tracks: n/a
  • iOS: Must have Spotify or Rdio subscription for full experience
  • Radio only

Bottom line: We’ll let you know in a month or two how it’s stacking up.

As new Internet radio and/or on-demand music services arrive, we’ll let you know. In the meantime, which service are you currently using?