Planning a lesson it`s not always the same since it depends of the level. My experience is with adults.

Warming up it`s ok you ask for activities they did yesterday or any time, life, family, job, make a joke etc. trying to exercise them of previous classes After you may change the focus and go to the introduction of the new lesson, and that`s no more than 20 minutes in full (up to you if you need more).

Then you go to your class. At this point I should say that starting with singing is not part of my classes in , let`s say, 75% of my classes. What I do is taking the singing as part of my classes, for example, I have videos which songs I choose carefully accoring to what I want the class to discuss. My favorite is Woodstock we hear songs, sing and talk about changes in music, the way hippies were an impact in american society.

Well, hope I helped

Take care

Jesus