I have been listening to the Will and Jace Podcast. Occasionally, they will have Katy Garretson, who was the assistant director. In one episode she talked about the gust stars. Her words:
"James Earl Jones was absolutely delightful to work with. He is such a professional, super easy, and super funny. No issues at all. He is exactly as you would think he is. Just a great, great man and a great actor.
You have also wondered if it was difficult to get big named guest stars like James Earl Jones. Oh my God, NOT AT ALL! We were "Frasier," We had credibility, we were respected, we were "smart," we were considered a "high brow" show, and we used a lot of theater directors and actors. We were known for being a quality show. Let me give you a list of some of the guest stars Frasier got over the years:
We had astronaut and Senator John Glenn;
Microsoft founder Bill Gates;
Patrick Stewart, Captain Piccard himself;
In the episodes I directed: Jean Smart, Emmy winner for one of my episodes. She thanked me. Which was super sweet and special.
Three time Oscar nominee Piper Laurie, who got an Emmy nomination. She was in The Hustler with Paul Newman and she was in the evil mom in Carrie. Also in that episode was Christine Baranski, who was also nominated for an Emmy in that episode.
We had Oscar nominee Laura Linney. In fact I directed her debut episode.
Also in my episodes were Oscar nominee Patricia Clarkson; and
Oscar nominee Felicity Huffman.
In other episodes we had Aaron Eckhart;
Michael Keaton, yes Batman himself!;
Amy Brenneman (She most known episode is Merry Christmas Mrs. Moskowitz, which is a fan favorite and one of the most adored episodes).
We also had Oscar nominee for Sideways Virginia Madsen;
Oscar nominee and Emmy winner Laurie Metcalf of Roseanne;
Shannon Tweed of Skinemax fame, married to Gene Simmons of KISS;
Recent Oscar nominee Richard Grant form Can You Ever Forgive Me;
Stephen Root, who is currently on Barry;
The gorgeous and super sweet Sela Ward;
Eva Marie Saint from On the Waterfront and North by Northwest, she was treat to have her on the show;
Brian Cox, who is now in Succession;
Sir Derek Jacobi, the great British stage and screen star; and
Mike Judge, the creator of Beavis and Butthead.
We could pretty much get anybody on Frasier. It was that kind of a show. It is one of the reasons Frasier is one of the best shows of all time on Television."