Could Chet read music?

Although some people, including Jack Sheldon, claimed that Chet was entirely an instinctive player, I am inclined to believe Russ Freeman, Chet's pianist in the 50s, that the trumpeter could read quite well (he did play in an army band after all), although his sight-reading was perhaps not up to Hollywood studio standard. Freeman goes on to say that Chet had little or no formal knowledge of harmony, which makes his improvisational skills, with their sophisticated harmonic explorations, all the more remarkable.