With shows like The Sing-Off, which has reached its fifth season, and movies like Pitch Perfect 2 grossing several hundred million dollars worldwide, a cappella music seems finally to have gained mainstream recognition, despite the fact that it's been enjoyed by audiences since the late 15th century.
Roderick Eldridge, who's the tenor, turntables and trumpet for the a cappella septet Naturally 7, says it's taken a long time for the style to become popular because it used to sound less exciting compared to songs performed with instruments. But since the introduction of vocal percussion in the early 90s, it has taken on a much fuller sound.
"Most of the time the music industry is just really behind. They wait and see if something works or gets popular before jumping on it," he tells Young Post in a phone interview.
Naturally 7 has struggled to find success. Formed in 1999, they have released seven studio albums, but despite their intricate vocal arrangements and performances with Coldplay and Michael Buble, they are not widely known.
But they remain upbeat. Having seven band members opens up a lot of possibilities, says Eldridge, including their signature "vocal play", which involves mimicking instruments, as well as beatboxing and harmonising.
This means they can have a lead singer, a bass, a beatboxer, three-part harmony and an extra instrument, like the horn or flute, at the same time.
"We can fill up the sounds like a band, but with the humanity of the voice. And there's just something about the human voice that just draws people in," says Eldridge.
As an a cappella band, they don't have to pay to transport instruments, or worry about technical glitches. "We're already a big band with seven guys so you split the cheque seven ways. You don't wanna spend any more money transporting gear around the world," laughs Eldridge. "The only problem is your guitar can't catch a cold."
The style is particularly demanding on the voice, as it offers no rest time. Once, a member of Naturally 7 collapsed during a show. "Sometimes we do these pranks on stage where one guy pretends to collapse but then jumps back up," says Eldridge. That time, however, "we were still singing, and then we realised …"
To maintain their voices, the members of Naturally 7 don't smoke or drink alcohol. They also avoid dairy products and cold drinks before a show because they tighten the vocal chords. Some of them do pushups to warm up and, as the vocal DJ, Eldridge plays with his voice, testing out the noises he needs to make. He demonstrates the range of scratching noises: "Owa- owa- check it out, Young Post!"
Eldridge has no problem mimicking most sounds, but he says the piano is the hardest instrument to imitate and nobody in Naturally 7 has managed to pull it off yet.
The group was in Shanghai earlier this month to judge the second Asian Cup A Cappella Competition at the Vocal Asia Festival. China's standard of a cappella still has room for improvement, so Eldridge encouraged groups to fuse traditional Chinese instruments into their arrangements to create original sounds.
For their newest album, Hidden in Plain Sight, released in April this year, Naturally 7 experimented with a Baroque choral style, layering classical music over hip hop beats. They were also the first band to get permission to mix recordings from Queen's Bohemian Rhapsody with their own arrangements to produce the upbeat Galileo. The new record also contains their reinterpretation of Coldplay's Fix You, a favourite at live shows.
The album cover art shows the group holding a flag with their logo, like revolutionaries.
"So much of pop music is artificial and auto-tuned, while lots of musicians creating good songs don't get enough attention," says Eldridge.
"We're crusaders trying to bring back real, good music to the forefront."