Here's a tip for the recording artist.
There is no need to show that you are versatile as a singer. That's not the point of an album. When a person listens to an album, they are looking to be entertained. The listener wants to feel happy. Wants to feel sad. Wants to get up and dance. Wants to be the singer. Your album is there for the listener. You are serving the listener while maintaining some artistic integrity and your personality. That's what an album is about. It's your personality or A personality in songs.
Be yourself. Tell your producer, your composer, your manager who you are and what you are about. Then make it work without being syok-sendiri-ing yourself. If your manager or label tells you to sing polka because it sells but you feel the life being sucked out of you when you sing it, tell your manager or label to go to hell or find another line of work. You will be better off in the long run.