Founded a decade ago in the Santa Cruz Mountains, heavy psych band Mammatus has evolved dramatically from its riff-rocking, robe-sporting early days playing house parties and dive bars.

The group's founders -- Emmert brothers Nicky (guitar) and Aaron (drums) -- had played together in earlier projects before teaming with bassist Chris Freels and second guitarist Mike Donofrio. It was the influence of Freels that led Mammatus to start adding elements of Bay Area experimental punk and doom acts like Neurosis and Sleep to their already lumbering Sabbath/Zeppelin riffage.

Quickly embraced as part of an established Santa Cruz neo-psych scene that included such notables as Six Organs of Admittance, Comets on Fire and Residual Echoes, Mammatus recorded a demo that soon had the band signed to deals with San Francisco-based Holy Mountain Records and British imprint the Rocket Record Company.

The band's eponymous debut and follow-up effort The Coast Explodes both showed off a sludgy, bludgeoning approach to epic psychedelia. The band toured the states with like-minded groups such as the aforementioned Residual Echoes and Japan's exploratory psych legends Acid Mothers Temple. But before long, Mammatus would go on an extended hiatus as band members settled into having jobs and families.

Finally returning as a trio with the departure of Donofrio, in 2013 Mammatus released Heady Mental through the Spiritual Pajamas label. The experimental album introduced new aspects to their sound, building songs around Emmert's extended finger-tapped arpeggios (think Eddie Van Halen guitar pyrotechnics meets minimalist composers Terry Riley and Phillip Glass) and adding Tangerine Dream style drone to the mix.

The band's new ambient/prog approach was hailed by critics and the band would be invited to perform at festivals like this year's stoner/doom celebration Psycho California. Mammatus headlines this record release party in Oakland at the Starline Ballroom Saturday night held in honor of its latest effort, Sparkling Waters.

Recorded with Phil Manley (Trans Am, Life Coach) earlier this year, the album continues the group's exploration of shimmering drones and extended progressive psych on its four 15-20 minute plus tracks, this time echoing Brian Eno's ambient work while still delivering plenty of head-nodding rock grooves. Joining Mammatus at the record release party will be songwriter Tim Cohen's band Magic Trick (also celebrating a new album on Spiritual Pajamas, the mostly instrumental Half Man Half Machine), finger-picking guitar phenom Matt Baldwin and a DJ set from Manley.

Saturday, Nov. 21, 8 p.m. $12-$15
Starline Social Club