If you want to hear several songs without having to be worry about illegal downloads.
I recommend this app.
Spotify is the king of music streaming. Every day tens of millions of users listen to thousands of tracks using it through a variety of different ways.
How to Install Spotify in Ubuntu
Spotify for Linux can be installed on Ubuntu 12.04, 12.10 and 14.04 LTS straight from the Spotify repository. This method is the recommended way to install the player as it allows you to get automatic upgrades to new releases of Spotify through Ubuntu’s Software Updater/Update Manager tool.
The first step is to open Software Sources via the Unity Dash:
Select the ‘Other Software’ tab in Software Sources 
Click ‘Add’  and paste the following the entry field of the box that appears:
deb http://repository.spotify.com stable non-free
Click ‘Add Source’ to confirm the change, then close Software Sources.
Add The Spotify Repository Key
The next step is to add the repository key. This allows Ubuntu to verify that packages installed from the repository are made by who they say they are.
Open a new Terminal window, paste the following command, and then hit return/enter:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 94558F59
That’s that! You can now install Spotify through the Ubuntu Software Center (after checking for software updates first) or by running the following command in the Terminal window:
sudo apt-get update && sudo apt-get install spotify-client
Once installed you can launch Spotify from the Unity Dash.
Credits: OMG Ubuntu