He should've rounded it off to an even thirty with an Axl Rose. I haven't heard a good Axl Rose impersonation for quite a while.
good question seigneur (always love your inquiring mind heh heh) anyha, maybe because it will be kind of hard to impersonate him. Axl Rose is on Top as the greatest singer ranked by vocal range :D
Here's The Greatest Singers of All Time Ranked by Vocal Range (http://www.concerthotels.com/worlds-greatest-vocal-ranges)
Here’s the top-ten:
1. Axl Rose
2. Mariah Carey
3. Prince
4. Steven Tyler
5. James Brown
6. Marvin Gaye
7. Christina Aguilera
8. David Bowie
9. Paul McCartney
10. Thom Yorke
(http://i59.tinypic.com/qzhp4x.jpg)