Giovanni Hoffer Improvised or read?

I've been listening to/seeing Giovanni Hoffer on YouTube and can't figure out if he's improvising or reading his "improvisations". He could just be looking at the changes. Anybody know? Thanks.

Hi Gary,
Giovanni is a good friend and I can swear that he doesn't need any music notes. When playing with a big band or any group, he may use as anybody some parts concerning new pieces or famous hits, but just to read the changes. Hoping to have to helped you.