First, make sure when you go to music that you sort your music by artist or album, otherwise it just lists every mp3 on your device.


Then to find a specific song after you have sorted all the music select the artist, then click, on the artist to see their albums, then click on the albums to see the songs in the albums. When you see a song you want to play/ add to a playlist, don't click on it or highlight it first.

Once you see a song you want, even if it's not highlighted, just press and hold it. If you're in 1 album and selecting one song it, the option to add to playlist should come up to let you add it to the playlist.
Maybe yours has a glitch?

I think you may be adding all library to playlist because you're selecting the song from the listing of every mp3 on your device(all library) instead of sorting them by Album or by artist first.


Hope this is a little helpful.