The best replacement for google play music is spotify.

The best alternatives to google play music are rated as following:
★★★★★  spotify
★★★★  itunes
★★  sound player
★★  xbox music
★★  poweramp
★★  itunes match
★  samsung music player
  walkman
  apollo
  deezer

Your alternative for google play music is not listed? Suggest!
Speaking about google play music, one probably shouldn't forget about poweramp.

Other search terms related to google play music and their ratings are:
★★★★★ poweramp
You have in mind a companion for google play music and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of google play music in all years. Click on graph for more.
google play music
spotify
itunes