It's hard to believe but ONDA is even more dynamic and rhythmic, with the permanent addition of Jaehyuk Choi (drums) and B.K Yu (bass), fixtures of Jambinai's live band since 2017. The way the quintet "sticks together like gears of a clock or machine," says Lee, is celebrated on Square Wave, a breathtaking example of Jambinai's ability to alternate between ambient serenity and molten ferocity.

Square Wave is also one of several ONDA cuts to feature vocals. "Voice and lyrics have strong energy, they can touch someone's heart directly more than instruments," Lee explains. "Also, most people don't know Korean, so they hear our voices as sound rather than meaning. We needed more sounds on this album." Not that the instrumental tracks are any less momentous. Take the opening Sawtooth (featuring Hwiseon Choi on yanggeum, a hammered dulcimer), because Lee thinks the band's constantly shifting dynamic, "resembles the sawtooth waveform of electronic sound."

Other ONDA song titles are similarly revealing. Event Horizon was suggested by a Jambinai fan to represent the music's, "strength and chaos", though the haunting folk instrumentation is never swept aside by the energy on display. Sun. Tears. Red is one way to describe Jambinai's emotional as well as visceral impact, punctuated here by hollering, anguished voices.

13 minutes long, In The Woods is the album's lengthiest epic, originally recorded for Jambiani's 2010 EP and now rearranged for the expanded quintet, plus guest traditional singer Bora Kim. The inspiration here is environmental pollution, soundtracked by eight minutes of mournful ambience that slowly builds to a shattering climax. "The earth is in serious pain," Lee concludes.

ONDA ends on a thematic note of drama and redemption. In Small Consolation, says Lee, "a person leads their weary body to a distant glow, which is small consolation. But when they get there, it turns into a big light, big consolation and happiness." The closing title track comes in two parts: a calm prelude (featuring Lee on saenghwang, a tall reed mouth organ) before the euphoric main course, graced by choral grandeur. Once the music dies away, the feeling is one of blissful exhaustion. The third wave of Jambinai is here. Come (Onda) join them for the ride of your life...