On Windows 10 I use the Spotify app from the Microsoft Store. You can see the shortcuts for playback etc in the menubar. The shortcuts only works if I turn off virtual PC curosr by JAWS+Z.

Here is a few key strokes:

Play=Space

Volume=CTRL+Down or Up arrow

Change track=CTRL+Left or right arrow

Seek=Shift+Left or Right arrow

Long time ago I try the desktop app but at that time I find the app from Microsoft Store to be much more useful. Maybe it has changed.

Here is the shorcut list from Spotify's site.

https://support.spotify.com/us/article/Keyboard-shortcuts/

I Think the best accessibility for Spotify will be find in the apps for phones and tablets.

Earlier I think there was some scripts available from some one called snowman but I don't remember what they do. As I remember they're not offered for free.

Seems they're no onger at his site but maybe you can try to contact him. The e-mail is listed at the site.

http://www.snowmanradio.com/scripts.html

OZ0TE Jacob