Since the beginning of time, or at least until Sony rolled out the Walkman, listening to music has been a stationary experience -- you went to the source of the sound, whether it was a bunch of tribesmen beating their drums or the stereo system in the living room.
But the Walkman and then Apple's iPod dramatically changed the way we listen to music. And now music apps are transforming the experience even more by turning smartphones into portable jukeboxes and radios.
Because there are so many music listening apps coming out these days it's hard to keep track of them. Here are our favorites for the iPhone and Android smartphones:
Pandora lets users listen to music for free by creating "radio stations" based on their favorite songs, artists or genres. The app will then play songs similar to the type of songs they like. Users can modify the kind of songs they want to listen to by hitting a thumbs up or down symbol for each tune. It's a great way to discover songs you may have never heard otherwise. If you aren't a paying user, you'll have to listen to ads every once in a while and there's a monthly cap of 40 hours of music each month that applies to smartphones and tablets. Users can pay a $36 annual subscription for ad-free, unlimited listening.
If you hear a cool song and want to know its title or who is singing it, Shazam is a nifty app that will help you find out. Simply hold up your smartphone and let the app listen. It will quickly figure out what song it is. Additionally, Shazam can be used to get information about a TV commercial or a TV show you're watching. The app is free but comes with ads. Users can get rid of ads by buying the Shazam Encore app for $5.59 for Android devices and $6.99 for iOS devices.
Think of SoundCloud as the YouTube for music and sound -- users and artists can upload music to the site for others to listen. Famous artists, like Beyonce, use the service to share new songs and remixes while up-and-coming musicians use the site to let others download their tunes. SoundCloud is also used by news sites to host audio, such as speeches by President Obama and 911 calls. The app lets users follow other users as well as comment and like each sound bite. The app can also be used to record and upload audio.
Amazon Cloud Player (iOS)/Amazon MP3 (Android)
If you purchase music from Amazon.com, you'll want to have its music listening app on your phone. The app can be used to stream music from the cloud or users can also download songs for offline listening. If you don't purchase music from Amazon, you can still use the app to store up to 250 songs that weren't purchased from Amazon. If you subscribe to Amazon Cloud Player Premium, which costs $25 per year, you can keep up to 250,000 songs in the cloud. The Android version of the app, Amazon MP3, also lets users purchase music on the app. The app is known as Amazon Cloud Player on Apple iOS devices.
Like Pandora, Spotify lets users listen to "radio stations" that they create on their smartphone. Users who subscribe to Spotify Premium, which costs $10 a month, can also stream any song from Spotify's catalog whenever they want. They can also create playlists and save them for offline listening.
Grooveshark, which is a Web app, works similarly to Spotify Premium and lets users listen to any song in its library for free. Unlike Spotify, though, Grooveshark is free except for a few small banner ads that show up on the screen while users search for songs. To access Grooveshark, simply open your browser app and go to grooveshark.com.
If your music takes too much space on your smartphone, Google Music is a great cloud service that will store your songs for you. The service will store up to 20,000 songs for free that iPhone users can then access by heading to music.google.com on their phones. From there, they can stream the songs to their device at a high quality. Google Music comes pre-installed for Android users.