Google play

If you don't like using the built-in tasker music player you can use the Android Music Player with intent to play a playlist.
1. Send intent
Configure
ACTION: android.intent.action.VIEW
DATA: null
TYPE: vnd.android.cursor.dir/vnd.google.music.playlist
EXTRA 1: playlistId:14L
PACKAGE: com.google.android.music
CLASS: com.android.music.activitymanagement.TopLevelActivity
TARGET: activity

Replace 14 with the playlist id# you want to play followed by L for long. You can find the playlist number bye creating a playlist widget for your home screen and running it through Intercept Intent http://intrications.com/