He has quite the versatile voice.
I find it interesting that he does the fast vibrato and the note embellishments at the same speed. The vibrato speed is a little fast for my personal taste, but I think it makes it easier for him to get in and out of the vocal runs from a sustained vibrato-ed note.
He has a great range and power.
I like the run with the glottal stroke at 3:39. You don't think he sings just about around the clock, do you? How about the fast enunciation at 4:30 saying slow down...
I like melismatic singing. I like gospel singers and their style.
At 6:08 a little taste of Journey...
This video has a lot of styles, all of which show off his voice.
Good motivational material. He seems to seek out rooms with a lot of natural reverb for phone recordings.
By around the clock, I mean that every waking moment is probably spent singing, no matter if it's morning, noon, or night.
The guy obviously loves to sing, and you don't get good at accurately executing tasteful runs by just opening your mouth one day and being able to do that. You have to start out more slowly and gradually build up speed and agility. You need really good breath control to sustain notes or phrases and then run down trills at the end of the phrase. It's like a melody line at the end of the melody line. You really have to work on your vocal chops to get this working well. Doing kazillions of scales and gradually speeding them up faster and faster is a way to build that kind of agility. As you memorize some runs, and eventually piece multiple runs together, you then do the same thing with the runs and trills. You gradually increase your speed and agility. Do this 24/7 or as close to that as you can, and eventually you, too, will be getting into this realm of cool, stylistic, melisma.