(Unheard of Hope)On their second collaborative album, the couple based in Mexico City add pop shimmer and thundering blastbeats to their unique, always-surprising soundIn just five years, Guatemalan cellist Mabe Fratti has become one of experimental music’s biggest names. In addition to her spellbinding solo releases, she is an eager collaborator, working with the likes of Efterklang, the improv quartet Amor Muere – which she co-founded in her adopted home of Mexico City – and with her romantic partner, guitarist Hector Tosta, as Titanic. On the latter’s superb 2023 debut, Vidrio, they pioneered a genre-agnosticism that veered from squealing free-jazz saxophone to hammering drum grooves and aggressively processed cello, always anchored in Fratti’s soaring falsetto. It heralded the arrival of a group who embraced experimentation as much as earwormy melodies.On Hagen, the duo double down on their convictions, complementing their unusual arrangements with a newfound pop shimmer. Opener...