You know how when you're listening to the radio, likely in your car, sometimes you listen to part of or the beginning of a song and then lose interest and change the channel? You were grabbed by the hook but the songs ability to hold your attention was not continuous. Is it not the same as when we prepare a lesson and lead off with a fun opener or activity to get students thinking about some piece of content, but then as we transition and move into the lesson, we lose students interest and attention? I think it is... and also why we need to be continuous in seeking the attention and interest of our students throughout the lesson. We also need to allow for breaks, speed up and slow down our tempo, and vary pedagogical techniques to keep up the learning experience for students just like music must do for listeners.