It's not random at all, he's just playing the changes, it's not even outside. Random notes would sound a lot different, maybe it's just rapid stream of notes th

It's not random at all, he's just playing the changes, it's not even outside. Random notes would sound a lot different, maybe it's just rapid stream of notes that don't sit well with you, that's the bebop sound, maybe you would appreciate (slow) blues improvisation more, or cool jazz.