AppleScripts that will post your currently playing tracks to a Slack channel of your choice using the slack webhook api.
Pull requests welcome. Lots of dirty hacks.
AppleScript for Spotify users. Set the webhook uri, channel, username and optionally a bot name (appended to the username when it posts to help identify messages), and it will take the currently playing song while the script is running and post it to slack with the album art as the profile picture.
AppleScript for iTunes users. As with the Spotify one, set the webhook uri, channel, username and optionally a bot name (appended to the username when it posts to help identify messages), and it will take the currently playing song while the script is running and post it to slack. No album artwork for this one :(