For the last fifteen years, Massachusetts sextet Caspian has explored the vast sonic expanse of post rock. Their palette has included glitching electronics, soft horn sections, gritty metal riffs, and the occasional vocalist.

On Circles, their fifth full length, finds them getting more experimental than ever before, without sacrificing any of their heaviness.

Reinvention is nothing new among post rock bands. Mogwai almost completely overhauls their sound every few releases. In 2016, Explosions in the Sky ditched the guitar-centric, climax chasing  sound they’ve perfected for the electronics-centric The Wilderness.

In certain moments, the arpeggiating synths, swirling pads, and drum machines suggest that Caspian might be ready to take a similar path. “Wildblood” opens with a wash of atmospheric electronics and an incredible saxophone solo (seriously, it gives me chills every time) that feels more Tangerine Dream than This Will Destroy You. But then, the guitars explode into a wall of distortion, and all is right with the world.

Throughout the record, the band continues to walk this balance between delicate ambience and crushing heaviness. “Flowers of Light” rides on an arpeggiated synth loop and acoustic guitar chords, adding shuffling drums and electric guitars until it bursts. “Onsra” spends its first half swelling with plumes of light chords, crashing with distorted crunch in its final half. “Ishmael” spends most of its strumming an acoustic guitar against glistening synths and delicate lead lines, but it’s last few minutes are classic post rock catharsis.

There’s plenty of classic loud Caspian here as well. “Division Blues” opens with a light electric guitar figure that repeats, swelling with angular drums and heavy bass until its inevitable climax. “Collapser” kicks in with a heavy riff almost immediately and headbangs throughout its entire running time.

Unlike most other post rock bands, Caspian isn’t afraid to add some lyrics where they’d serve the song. This record has two such tracks: “Nostalgist,” which features Pianos Become the Teeth’s Kyle Durfey singing over Caspian’s triple guitar work, and “Circles On Circles,” a folksy acoustic ballad mourning the loss of things that were. For a band that doesn’t usually traffic in vocals or lyrics, Caspian makes surprisingly affecting use of both.

I didn’t think I would ever love a Caspian record more than Dust and Disquiet, but On Circles is closely edging in. It takes everything I loved about the previous record and stretches further. The band manages to expand their sound while sounding even more like themselves.

And since this is a vinyl blog, I would be remiss to not mention the packaging job on this. Both the front and back covers are embossed, the thick spine has a splash of rainbow that somehow doesn’t clash with the minimalist cover art, the liner notes are spread across two well-designed 12X12 glossy pages, and it has a gorgeous obi strip, which I can never resist.

I know it’s only February, but I’ll be pretty surprised if this record doesn’t end up in my top five this year.