04/17/2012 02:05 pm ET Updated Jun 17, 2012

Smash 's Ellis on Uma Thurman's Musical Theater Chops: 'She's Actually Very, Very Good!'

When we ran into Ellis from NBC's musical drama series Smash, we couldn't help but squirm. Jaime Cepero's character is all ambition, no conscience: from sexual favors to backstabbing, he'll do anything (and anyone) to get ahead on Broadway.

Rest assured, the baby-faced scoundrel was nothing but nice in person. But in true Ellis fashion, Cepero did spill what it was like to work with Uma Thurman -- who plays Rebecca Duvall and the new star of the musical-within-a-musical Bombshell in the show -- the worst part about filming in NYC, and the most valuable thing he ever lost.

What was it like working with Uma Thurman on the show?

She's really cool, really down to earth, very professional -- she comes in and does her job. She's on a five-episode arc and she does several musical numbers. She's actually very, very good. I was really impressed.

How many hours was she there on set?

We do a lot of takes just because we always do a rehearsal take then a fantasy one. She took to it like a duck out of water. She's really committed. Usually we're there from 6 a.m. until 9:30 at night. And she was there the entire time on the days she was on set.

How good was she?

She could sing -- she sang in The Producers. There's a great jazz episode coming later where she does all the big scenes. People are going to be really, really impressed. I only had like two scenes with her, but my character always lingers in the background, so every time we were on set together, she was so professional and pleasant and so funny. She has some really great comedic moments, so I think people are going to really enjoy her on the show.

What's the worst part of shooting in NYC?

The worst part is having to deal with all those people -- there are so many people. People want to stop and take pictures or stop and ask questions and you're like, "I have to do a scene, I'm sorry." That's the toughest part. It really depends. We did a shot in Grand Central Station and that was the toughest one -- so many people moving in and out and we kept having to reset and walk to the train and people would like stop us and want to take pictures with Cam and it's like, "We don't have time for that; we're shooting our TV show. Give us a minute. I promise I'll sign it, just give us a minute." We did a scene in Times Square, too, so it's pretty busy, but we got through it.

What was the most valuable thing you ever lost?

One time I had cut my rent check and then went food shopping on the way home, so when I got upstairs I realized that I dropped it somewhere. I went back to the supermarket and I just called and canceled it. It was a terrible 45 minutes. It was like $1,600. I was living in Harlem at the time, on 145th Street and St. Nicholas Ave.

Do you still live there now?

No, I just moved to Hell's Kitchen. This is pretty temporary. I had to move pretty quickly so I could be around for shooting.