Justin Guarini, who rose to fame on the first season of American Idol, has since become a regular presence on the Broadway stage, appearing in Wicked, American Idiot, Women on the Verge of a Nervous Breakdown, and the recent revival of Romeo and Juliet. The acclaimed singing actor is currently back on the New York stage, playing the role of Trent in Broadway's first a cappella musical, In Transit at the Circle in the Square Theatre. Here, Guarini shares the theatrical performances that most affected him as part of the audience.

Colm Wilkinson in Les Miserables

I'll never forget my first Broadway show. I had the honor of witnessing Colm Wilkinson perform as Jean Valjean. I was in the front row, and even at a young age I could feel the gravitas that he brought to the role. His voice was, and still is, immaculate.

Revival of Working

There was a beautiful revival of Working, directed by Gordon Greenberg, at 59E59 Theaters that was so intimate and touching. The entire ensemble gave an outstanding performance because of how artfully they played multiple roles and how well they supported each other in the process. I love when people take risks in theater. They did, for sure...and in my book, it paid off.

Candy Buckley in Bucks County Playhouse's Company

I consider myself an extremely fortunate actor who works often, but as a result don't get to see as many shows as I would like. So...this is a performance that I had the honor of watching eight times a week: Candy Buckley playing Joanne in The Bucks County Playhouse production of Company, directed by Hunter Foster. As Bobby, I loved watching Candy work. The depth and frightening beauty she displayed each night, especially in the last scene where Joanne is pushing Bobby to confront himself. I'll never forget her hands...how delicate and beautiful they were (and still are), as they held her rocks glass full of booze. I tried not to smile too much as she wowed the audience every night with her powerful rendition of "Ladies Who Lunch."

Matthew Broderick in How to Succeed in Business without Really Trying

Another one of my early Broadway experiences was How to Succeed... starring the one and only Matthew Broderick. Besides his iconic performance, one of my fondest memories from this performance was actually a mishap during the show. When Finch finally becomes the CEO, Matthew had to jump backstage for a quick change into his next outfit. Well, the other actors were standing on stage near a set of double doors, clapping...and clapping...and clapping some more. Probably 10 seconds went by (an eternity of time on stage), and Matthew popped out of the doors with a waggle of his brows and a meaningful look at his castmates. I remember it so vividly. I was 15 at the time, and I couldn't put my finger on what was wrong, but there was a feeling in my gut that something was off...it wasn't until many years later when I had my very own quick change on Broadway and understood how daunting the task can be (even at the best of times) that I realized how well he and his dresser(s) handled the situation.

Jennifer Holliday in Dreamgirls at The Muny

In the sweltering heat of St. Louis, I had the joy of watching Jennifer Holliday play what was billed as her last-ever performance of Effie in Dreamgirls at The Muny a few years ago, and she was nothing short of majestic. She played the role with as much vigor and grace as she did years ago in the footage of her iconic Tonys performance. I truly feel blessed to have been a witness to living history.

Michael Crawford in The Phantom of the Opera

Michael Crawford in Phantom...the OG!!! I was terrified of this soundtrack as a kid because of the massive organ and the screaming...and, of course, fell in love with it when I saw Michael play the role.

Kelli O'Hara in Peter Pan

Even though it's on TV, it's still theater—Kelli O'Hara in Peter Pan on NBC. I'm sorry/not sorry, but she was the way, the light, and the truth in her performance. Pitch perfect, and done with an elegance that is second to none. I was sad she didn't have more to sing!

K. Todd Freeman in Airline Highway

I had the joy of working with K. Todd during my time as Fiyero in Wicked and loved seeing him step into the sassy role of Sissy Na Na. He is a phenomenal actor and someone who deserves all the praise he gets. I rarely get the chance to see plays...and this one was a treat.

Ne-Yo in The Wiz

Again, it's not the traditional way to watch theater, but it's such a valuable resource to our industry: Ne-Yo in The Wiz on NBC absolutely blew me away. We all know he's a talented writer/producer/vocalist...but the man can act, too! He almost stole the show in my book. I don't even know him, and I was so proud of him!

Billy Joe Armstrong/American Idiot

In my final Broadway performance as Will in American Idiot, Green Day did a concert to close out the run. All their hits, all of the cast on stage, and the entire audience going wild. It was truly a rule-breaking evening on so many levels...but hey, American Idiot shattered a lot of rules and a lot of stereotypes. Watching Billie Joe and the boys tear up the stage at the St. James Theatre (which we lovingly called the St. Jimmy Theater) was a once-in-a-lifetime event.