Spotify is a digital music service that gives you access to millions of songs.
This internet music service allows you to select any song in it's database and play it for free. This service was recently only open in areas of Europe, and has recently (07/17/2011) been opened up to the United States area. The only client currently available on linux is supported on Debian and Fedora distributions, while they do recommend use under wine.
If you already have a copy of wine installed; you can skip to the step listed below for sound configuration.
# pacman -S wine
Configure the sound
# wine cfg
Run the wine configuration menu from a terminal under the user you wish to use regularly, under this application you will have a tab called Audio. This tab contains the settings for sound emulation under Wine itself, the website recommends using OSS under a screen shot of a different operating system. However you can use ALSA if you are not an OSS user, and the only requirement is to change the Hardware Acceleration to Emulation from Full, if you do not you WILL have issues with playback.
Once you have the client you can install it using wine from your preferred user account (not root):
# wine Spotify\ Installer.exe
And of course, after installation you can run it from the ALT+F2 menu, or the Wine menu, or the terminal:
If you use a x86_64 copy of ArchLinux, you'll have to run it like this:
# wine "/home/username/.wine/drive_c/Program Files (x86)/Spotify/spotify.exe"
If you use a x86 copy of ArchLinux, you can use this command just fine:
# wine ~/.wine/drive_c/Program\ Files/Spotify/spotify.exe
If you have any additional problems, I recommend setting the winecfg to Windows XP or Windows 7 emulation.