With their eponymous debut, Brazil’s legendary Os Mutantes may have released the most bizarre album of 1968, a year filled with absurdist pop performances and aesthetic experimentation. The album was a discordant cacophony of noise, tape loops, and enough sinister lead guitars to make Lou Reed cringe. The group is reunited on Haih Or Amortecedor for their first studio album since 1974’s Tudo Foi Feito Pelo Sol, but the reunion is mostly in name only. The ethereal vocals of Rita Lee are replaced by the at times shockingly good Bia Mendes, and the sole original member on the album—founder and guitarist Sérgio Dias, admittedly the group’s most important contributor—does everything he can to reproduce the group’s scathing ‘60s psychedelia.

He comes close at times. The majestic songwriting of music legends Tom Zé and Jorge Ben certainly helps. The soft pop of “Teclar” is filled with enough extraneousness to distort any of the music’s pop conventions and make listeners raise their eyebrows. A droning cello, electric slide, and vocal harmonies that sound eerily like the Dirty Projectors who have been avid listeners of the Os Mutantes for years, and a melody that refuses to stop rising in intensity make the song sweat. “2000 e Agarrum” is pure circus music—albeit a circus you’d never want to go to, that you probably wouldn’t return from alive. It’s the best example that, while other ‘60s relics have mellowed or disappeared entirely, Os Mutantes have only become weirder. There are moments of avant-garde exploration here that are so bizarre, the music feels like it could disintegrate. Yet Os Mutantes have complete control of their zaniness, and Haih Or Amortecedor is never arduous.

Most interesting is the group’s use of natural instruments to create their bizarre sounds. “Bagdad Blues”, for instance, alternates between sexy and psychotic, with the song’s schizophrenia being pushed along by only an accordion, a horn section, and a flute, commanding the song’s experimentalism.

That the group can do so much with so little is the album’s strength and, ultimately, its downfall. It’s a subtle fall, certainly not biblical in its scale, but Os Mutantes do get carried away at times, and, at others, become too muted. The frenetic flutes and too-calm organ work create an aura of both genre-bending avant-garde or early ‘90s smooth jazz, sometimes within a single song. It works sometimes, adding to the entirely nonsensical, wonderfully structureless songwriting, but also results in music that is merely inconsistent. Yet the other-worldly harmonies—not for nothing does the group’s name translate to “The Mutants”—keep the music mostly in an intriguing, gloriously antithetical realm.

What’s most noticeably missing, however, is the delicate baroque pop of “Baby” and the meditative blues of “A Minha, Menina”. If anything, Os Mutantes have stayed perhaps too faithful to their Tropicalia roots with Haih Or Amortecedor, forgetting that some of the highlights of their early career came from moments of reflective minimalism, oozing with sweetness.

Still, in spite of the occasional misstep, Haih Or Amortecedor is rhapsodic, an endearing tribute, and a welcome addition, to one of pop music’s strangest group of musicians.