[edit 20 Mar 2015 - the most recent update 126.96.36.199.xxx still contains the problem]
[edit 21 Apr 2015 - 1.0.3.x doesn't seem to seem to have this particular problem. Some users are finding a different problem, although for some users things are working fine and we're not clear yet whether the newer problem is related to a version of spotify or a version of OSX]
Reason: Applescript is broken in this version of Spotify. I'm sure it's an oversight on their part, not a permanent removal. There are helpdesk calls open and I'm hoping that they will fix and release an update soon.
Workaround: This hack. The post assumes a certain level of knowledge, so in case you need it, here are the steps with images.
1. find your Spotify app in your Applications folder. Right-click / control-click and choose 'show package contents:
2. Browse and find the info.plist file within the Contents folder.
4. I found that this only worked after a restart. Note that this could break the code signing of the app and so depending on your security levels you may be asked to allow Spotify access to things or even to allow Spotify to run.
5. If Spotify updates itself (which it does frequently) and they haven't fixed this problem in the next update, then you may have to go through these steps again.