Listen to the pop duo's song selections with a Spotify playlist.

Merrill Garbus sings about racism, white privilege and climate change on the experimental duo's fourth album.

The Hollow formed in 2013 and released its self-titled debut EP two years later. Since then, the Denver rock band has been fairly quiet while retooling its sound and lineup by recruiting former Epilogues drummer Jason Hoke. The quartet is back this year with the guitar-heavy EP "Contact," recorded in Evergreen, Colo. The Hollow made its debut in the CPR Performance Studio earlier this month. The band members played four songs and spoke with Alisha Sweeney about the new lineup's first year together, using drones to film the music video for "Sleep Talkin'" and how writing their music is therapeutic.

Since playing a session in our studio last year, iZCALLi wrote and recorded its fourth album. The Denver rock band released "IV" last week with a show at the Bluebird Theater. The self-produced record finds the band expanding from a trio to a quintet and continuing to blend English and Spanish lyrics with Latin and psychedelic music. iZCALLi played three songs from the new album in the CPR Performance Studio. The band members also spoke with Alisha Sweeney about expanding its sound with strings and horns, integrating Latin rock into Denver's music scene and their experience as U.S. immigrants over the past year.