How Old is TOO OLD to become a Rapper?

Mobb Deep's Havoc has a theory about older rappers -- "If you haven't already gotten on, and you're past 30...try something else."

• Havoc, who's 37 but has been in the game since his teens, says Jay-Z (who's 40) and Eminem (who's 38) have already proven themselves and could rap into their 50s.
• Others getting up there in years include Nas (who's 36), Raekwon (40) and Rakim (42).
• Currently, the only rapper older than 30 in the Top 10 on Billboard's Rap Songs chart is Ludacris (who's 33).
• The rap genre itself is only about 40 years old.

Kenny Asks:

• How old is too old to rap?
• Should a rapper retire at a certain age? Or should album sales trump age (As in the case of Jay-Z, for example)?
• How much old-school do you listen to? What appeals to you?