In one sentence, describe what the following article is about:

If you try to edit a playlist while music is playing, a bug can occur that keeps you from being able to save the playlist when the track changes. to prevent this, pause playback when creating and editing playlists.  You may have to "pull down" on the list of playlists with your finger to get the "New Playlist" button to appear.  Opening the Songs tab will list all of your available songs, while the Artists and Albums tab will allow you to view individual artists and albums. You can only add individual songs, so if you want to add an album you'll need to add each song from it. If you have "Show All Music" enabled for your iPad, you'll be able to add any of your purchased songs. Otherwise, you'll only be able to add tracks that are stored on the iPad To add any of your music to your playlist, see the next section. You can always open it again and tap "Edit" and the "+" to make changes to it. If the "Done" button turns into a "Now Playing" button, then you likely had music playing while editing the playlist and the song changed. You'll need to pause your music and start over. If you added songs that you've purchased but not downloaded, you'll see an iCloud icon next to each of them in your playlist. Tap the iCloud icon to begin downloading the song to your iPad.

Summary:
Open the Music app. Pause any music currently playing. Tap the Playlists tab. Tap "New Playlist" at the top of the list. Enter a title for your playlist. Tap the "Songs", "Artists", or "Albums" tab. Tap the "+" button next to each song that you want to add. Tap "Done" to finalize your playlist. Download any songs you need to on the list.