Recently Spotify started sending notifications to the desktop on song change. This is unnecessarily annoying and breaks my flow, so it had to go.
(and since I usually just listen to the same playlists anyway, I’m very well aware what the song name is ;-))
This appeared after a recent apt-get upgrade on my Debian Jessie machine. The interwebs is full of helpful advice on how to fix this on your Mac (growl something something), but not so much for Debian Linux.
The nice Archlinux people knew how, however:
After version 0.9.10, track change notifications were enabled by default. They can be quite intrusive. To disable them, add the following line to ~/.config/spotify/Users/<spotifylogin>-user/prefs
ui.track_notifications_enabled=false
It is also possible to launch spotify with the –ui.track_notifications_enabled=false option.
Works like a charm. Perfect. I’m using version 0.9.10.17.g4129 of spotify-client from their apt-repository.
Blog of Lasse Karstensen 
my problem was that spotify was like freezing my desktop for 2 seconds while changing to the next song, using debian wheezy. disabling the track notifications like you mentioned above solved that, so, thank you! :)
Great! I finally solved this annoying problem of a freezing desktop every time the song changes. Thanks a lot!
a ‘killall spotify’ is handy to force reload settings. Worked like a charm, thanks!
Worked great, thanks! Ubuntu 15.04
FYI it’s now possible to disable it from the GUI