Which of these musical elements is usually not altered for improvisation?

Ineed some on finding music. i have a nephew who is into rap, but when i find a rap song, it seems to either be too old for his taste or to him it isn't good enough. can someone suggest some good music for me to see if he likes it or not?

Oldest to newest jazz in order apex blues swing cool new orleanes jazz

What should i say so i can switch my instrument