By Sierra Marquina

Katharine McPhee called in to “On Air with Ryan Seacrest” and shared with us how upcoming guest star Liza Minnelli was a total “hoot” on Smash.

Smash season two “has definitely changed” says the singer. Adding, “it’s still basically about theater but we have a little bit more drama and a little bit more romance.”

As for the surprising list of guest stars, including legend Liza, Katharine shares: “I’m a little bitter about all the guest stars…I didn’t get included on all these guest star equations…I missed out on Sean Hayes, I missed out on Liza…but from what I hear, Liza was an absolute hoot…kind of unpredictable…you didn’t know if she was going to say the line she was given or not.”

We can’t wait to catch Liza on Smash. Be sure to catch the season two premiere back-to-back special of Smash tonight on NBC at 9/8c.