It always bothered me that Spotify doesn't have an icon on menu bar; so I decided to create one. With "Spotify - now playing" you can, easily from the menu bar, see information about the current track, control the playback (previous track, pause/play, next track) and add the current track to your library or playlist. The code and app to download it's here https://github.com/davicorreiajr/spotify-now-playing.
Spotify now playing
Menu bar app that shows currently Spotify playback and allows you add songs to playlists and library