Fade Spotify and then play specific song

#!/bin/bash
osascript <<EOD	
	display dialog "Ready to play song?"
	
	tell application "Spotify"
		set current_volume to the sound volume
		if (player state is playing) then
			repeat
				repeat with i from current_volume to 0 by -1
					set the sound volume to i
					delay 0.05
				end repeat
				pause
				set the sound volume to current_volume
				exit repeat
			end repeat
			set the sound volume to current_volume
		end if
		pause
		play track "spotify:local:::iStock_000021410538Wav48000:173" in context "spotify:user:col16:playlist:20gspPN5TiwzVNqnciD7uT"
	end tell
EOD