Are your students telling you, or are you getting the idea, that they just don't understand what you are saying because "you are old and can't relate"? (I'd crush any kid wh told ME that...) Have students present science their way. What is their way, you ask? They are more than happy to present a description of the skeletal system, or any other science topic, using a 'rap' song format. Invite the students to perform their work live to the class "audience" and/or visiting administrators.
Be advised: As with all things in life, make sure they understand that they are performing in a school setting and the typical callous and insulting language used in some popular rap songs will not be acceptable. I'd suggest threatening them with punishment of being forced to listening to 4 hours of Barry Mannilow if decorum is breached. That oughta stop them.