In the center is JD Sumner (bass singer, he works with Elvis from 1971 to 1977). Elvis called him friend. Pretty famous singer, as I know he's even was included in Guinness Book of Records (the most lowest voice). I don't know who is other people, maybe friends of JD Sumner. It's strange because for friends Elvis signs autographs with long description.
Wait for more opinions. I think this autograph has a good chance to be real (it seems to me.... but I'm not sure on 100%).
I see more positives than negatives. Not sure but could be authentic.
The same feelings.
This one's above my pay grade, but I agree with Terrier, I think it has a decent chance of being real. I'm far from confident on it, though.
I also think it stands quite a good chance of being legit;- can also see quite a lot of positive things about it