How do I get iTunes 11 to work as the old iTunes did in this respect: after playing a song in one playlist, I click on another playlist, highlight a song, press play, and get the result of that song playing & that playlist continuing?

Question

   How do I get iTunes 11 to work as the old iTunes did in this respect: after playing a song in one playlist, I click on another playlist, highlight a song, press play, and get the result of that song playing & that playlist continuing?  As it goes now, one clicks on the song in the new playlist where the arrow is and then chooses 'Play Song Next.'  So, it plays next, but then the song after that is back in the old playlist.  I want to use iTunes smoothly without the extra clicks I've had to do in order to get the playlist to continue.  This is music for background while I play the violin at restaurants, and extra clicks and hassle is quite unappreciated, especailly since it worked fine in the previous iTunes.
   Thanks.

Answer 1

At the top of the playlist where it shows the playlist title and the number of songs, there are two icons. Click the "play" triangle to add the entire playlist to "Up Next", or the "shuffle" symbol to do the same thing but in random order. But the currently playing track will stop playing, and all the songs in "Up Next" will be removed (replaced by the ones from this playlist).
If you hold down the "option" key while clicking those icons, the currently playing song will continue playing, and the new playlist will be added to "Up Next" (above the songs that were already there).