Spotify on Linux now supports all Spotify accounts, offers 15 million tracks for free accounts.

Install Spotify desktop client in Ubuntu:

This is a preview build of Spotify for Linux. .deb packges for Ubuntu user are available from Download appropriate one and double click to install via Ubuntu Software Center.

If you want add the spotify repository and keep it updated, open up a terminal window and do following steps:

# 1. Add this line to your list of repositories by editing your /etc/apt/sources.list

sudo gedit /etc/apt/sources.list

deb stable non-free

# 2. If you want to verify the downloaded packages,
# you will need to add our public key
sudo apt-key adv --keyserver --recv-keys 4E9CFF4E

# 3. Run apt-get update
sudo apt-get update

# 4. Install spotify!
sudo apt-get install spotify-client-qt