"It might be thematic work. It might be theatrical. I enjoy that kind of work"

John Sebastian is expressing his gratitude for the kind of work that is both thematic and theatrical. He is suggesting that he enjoys the combination of these two aspects, as they can develop a distinct and powerful experience. The thematic aspect of the work permits a deeper exploration of the subject, while the theatrical aspect adds a layer of drama and excitement. By combining these two aspects, the work can end up being more appealing and significant. Sebastian is most likely referring to the kind of work that he has actually performed in the past, such as his work with The Lovin' Spoonful, which typically included both thematic and theatrical components. He is expressing his appreciation for this type of work, and his enthusiasm for it appears.