MANILA -- After dazzling the Manila theater scene with such gems like “Newsies” and “Himala,” expectations are high as 9Works Theatrical presents its first-ever original musical “Eto Na! Musikal nAPO!” which opens on Friday.

But writer and director Robbie Guevara is confident about the musical which features the songs of OPM icons Apo Hiking Society.

“These are the things you can expect -- the Seventies, nostalgia, lookback. Music will be fantastic because of the very foundation of the songs. It’s Apo Hiking Society, how can we go wrong?” Guevara said.

The idea of doing a musical based on the trio's songs had been percolating in Guevara’s head for some time now.

Asked about how “Eto Na! Musikal nAPO!” started, he quipped, “It’s all Buboy’s fault,” referring to Apo Hiking Society member Buboy Garovillo.

While guesting on 9 Works Theatrical’s production of "Grease" in 2013, Garovillo casually mentioned that they should make a musical based on Apo’s songs.

Another Apo Hiking Society member Jim Paredes admitted that there have been many attempts to mount a musical based on their songs. But he felt that this was the first time someone was really serious.

“These are theater people who loved what they did," Paredes said of 9 Works. "The way the songs are interpreted and situated, it was very pleasantly unexpected.”

While the story and plot are still under wraps, the musical's outline is based on Garovillo’s own stories about their group. Guevara used these tales to create a story of seven friends, three of whom achieved fame and fortune, while the other four went on their separate ways. Since “Eto Na! Musikal nAPO!” is set in 1975, these events unfold against the backdrop of Martial Law.

At first, Guevara was sensitive about including aspects of Martial Law. But then the members of the group believe it has to be included. “It was an un-ignorable circumstance of the time,” Apo Hiking Society member Danny Javier told Guevara.

(Javier’s son, radio DJ Jobim Javier, is making his stage debut in the musical.)

Guevara, however, clarified: “I didn’t do the script alone."

"There was another member of 9works who actually knew more about Apo songs than me, and I would bug him all the time when I was stuck,” he added, as he acknowledged the contributions of 9 Works' PR manager turned dramaturg Jonjon Martin.

“I wanted to show how simple life was before. Some of these simple things aren’t appreciated today. Even if things were simple before, people were happy and had purpose,” Martin said.

With the Apo’s huge catalog, it was a challenge to choose songs to include into the musical. Musical arrangers Daniel Bartolome and Orly Dela Cruz really went to town with the arrangements.

Film and theater actos Mark Bautista leads the cast of the musical as the group’s chief lyricist. Joining him are Javier and Rita Daniela, who was in West End and Seattle productions of David Byrne and Fatboy Slim’s "Here Lies Love."

Also in the cast are Filipino-Japanese actress Marika Sasaki, Jon Philippe Go, Jef Flores, Sab Jose, Alfritz Blanche, Jon Abella, Neomi Gonzales, and "Miss Saigon" alumnus Raul Montesa.

Paredes hopes millennials would watch the musical.

“I want younger kids to watch it because I want the millennials to know how cool their parents were,” he said, adding that the group has always wanted to write for Filipinos "songs about love, friendship, relationships, sex, the wonder of life and all of that."

"This is, without even planning it, our legacy.”

Globe Live! And 9 Works Theatrical’s production of "Eto Na! Musikal nAPO!" runs at the Maybank Performing Arts Theater, Bonifacio Global City, Taguig on August 3-5, 10-12, 17-19 and 24-26, with shows at 8 p.m. on Fridays, Saturdays and Sundays, and 3 p.m. matinees on Saturdays and Sundays.