I tried uploading a video for this, but the forum won't allow a 10-second screenshot.
Create a playlist, add a song, go into the playlist,
You'll see the Playlist toolbar (the first time) with the +, playlist volume, dropper, etc.
Then click the name at the bottom to enter the lyrics display. No need to even play the song.
Then click back on the title where it says "tap to close".
Playlist toolbar has now vanished.
It comes back by having to click Edit > Done.
Does this on both my iPhone and iPad, both on versions 3.5.4