Spotify Play Button can easily be added to post or page for instant play of album, playlist or song. Oh, and it has an admin page in WordPress too.
This section describes how to install the plugin and get it working.
Upload the folder "spotify-play-button-for-wordpress" to the "/wp-content/plugins/" directory
Activate the plugin through the "Plugins" menu in WordPress
Go to "Spotify Play Button Settings" under the "Settings" menu (http://YOURBLOG/wp-admin/options-general.php?page=spotifyplaybutton_settings) to make your default settings for your Spotify Play Buttons.
Start adding your Spotify Play Buttons!