At the same time, Rivera's good friend and classmate Ema Mitrovic was auditioning for the North Jersey Region 1 chorus, having made the all-star chorus the previous year.
When the buddies became the only two performers from Hudson County to make the prestigious band and chorus, they celebrated the way teenage girls can do.
"We screamed a lot," Mitrovic laughed.
So when the auditions came for another go-around for the Region 1 band, the two, now seniors at North Bergen High School, should have been veterans at it, right?
"I was extremely calm," Rivera said. "I didn't even know whether I was getting jitters. Last year, it was insane, trying to get ready, learning a new instrument. It was a lot better this year. Since I made it last year, I had a lot of confidence."
However, Mitrovic didn't have the same feelings as her friend.
"I was a nervous wreck," Mitrovic said. "I made it for two years and I was more nervous now, because it's my senior year and I didn't want to not make it my last year."
Neither student knew what they were in for when they auditioned recently for the North Region 1 band and chorus. Only about 100 students throughout the northeastern part of the state were to be selected, and the audition process at Waldwick High School was mentally grueling.
Rivera was asked to first perform a solo to a piece of music provided by the judges. Then Rivera was handed a piece of music and was asked to read it and then perform the sheet music in less than a minute.
If that wasn't enough, Rivera was then handed a stack of cards and she then had to perform scales using the cards. Any slip-up in that process would have been a disaster.
"I had been practicing a lot with the bass clarinet," said Rivera, who has been playing the standard clarinet since 4th grade but picked up the bass version last year for the first time. "I've been practicing like crazy, so much that I think I'm now equally talented in both. It's a big instrument to play and I'm really only a couple inches bigger than it when I sit down. It takes so much longer for the air to get where it has to get."
Mitrovic, who also plays the saxophone in the school band, was concentrating on her vocal skills once again. She made the mixed chorus as a sophomore and the all-girls' chorus last year.
"I'm all over the place, between the band and the chorus," Mitrovic said. "I got into performing when I was a student at Robert Fulton School and joined the chorus there. I've been singing ever since. I like performing. I would like to be a musician or an actress after high school."
Mitrovic's audition was very similar. The judges had no idea that she was already a two-time honoree.
"They didn't know me by name or what I did," Mitrovic said. "They only knew me by number. I had to start all over again and that made me a little nervous as well."
Their persistence in auditioning paid off, because both young ladies will represent North Bergen High School in the North Region 1 concert at Secaucus' Arthur Couch Performing Arts Center on Feb. 10.
The two friends are the only musicians from Hudson County selected to perform at the concert.
"It's wonderful that we made it again," Mitrovic said. "I couldn't stop screaming when I found out. I think the whole building heard me."
"It's so great," Rivera said. "We were pulling for each other to go again. It's what we were hoping for. It's the coolest way for me to enjoy my senior year, a great way to go out."
Rivera did so well in her audition that she will be sitting first chair at the Region 1 concert.
"When I heard first chair, I was first in denial," Rivera said. "I wasn't accepting congratulations because I thought it was an error."
North Bergen Band Director George Haviland is proud of both of his students and their accomplishments.
"To have two of our students represent our high school among all the other great musicians in the state is a great accomplishment," Haviland said.
Haviland said that Mitrovic worked with the district's music supervisor, Dr. Myke Leshowitz, extensively before the auditions.
"He was the final factor," Haviland said. "He gets the final say as to who auditions. I think honors like this just build up the music department's background. It's another feather in our cap."
While Mitrovic has already applied to Rutgers and New Jersey City University to study music as a voice major, Rivera is will go to Rutgers in the fall and study English.
"I might want to major in English to become a teacher or journalism to become a writer or an editor, because I like writing," Rivera said. "But I know that I will be involved in music in some capacity."
Rivera will also get a chance to audition for the All-State symphonic band this weekend in J.P. Stevens High School in Edison.
"I think she's going to make it this year," Haviland said. "She's the first chair for the region. When you're the first chair, you're the best in that section, so that's why I think she has a shot to be all-state."
Rivera knows that her buddy is destined for success.
"Singing is her calling," Rivera said. "She's super talented. I just play."
"We're awesome friends," Mitrovic said. "I'm so glad I can share this all with her."