When the Windows Phone 8.1 preview rolled out, its music app was underwhelming; you couldn't use Cortana voice commands for everything, and it was fairly buggy. Both of those gripes are gone now that Microsoft has updated the music client with its latest mobile OS in mind. You can now use voice to do most anything, including starting playlists by name; you no longer have to go hunting for that collection of hot summer jams. Problems with unexpected black screens should also be gone, and interface transitions should be smoother across the board.This is just a hint of what's to come, too. Microsoft is promising a series of updates that bring Live Tile support, initial background syncing and more intuitive playback controls. You should see the next upgrade sometime within two weeks, as of this writing. If there's something you don't like now, there's a chance that Redmond will fix it in short order.