I disagree with the first statement. Because I do songs with my students, I choose the songs according to their ages, likes and topics. Music is for all ages it´s an extra source because we can practice pronunciation, listening and grammar.
I agree with the second statement. We have to practice and review the previous vocabulary in order to use it or link it with a new topic.
I agree with the third statement , because our students have different kinds of learning, some are faster than others , so we can give them an extra activity or they can help or explain their classmates.