Brittany Howard, frontwoman of blues rock sensations Alabama Shakes, has unexpectedly put out her second album within the space of a few months -- this one as part of a side project.

The new album is entitled "Thunderbitch" by a band of the same name that includes Howard and members of lesser known independent acts.

The band released the album late Tuesday with a minimalist promotion strategy. The album is streaming for free on the band's website, where a biography of the group reads succinctly, "Thunderbitch. Rock 'n' Roll. The End."

The website also features a short video for "Heavenly Feeling," the last track on the album, which shows nighttime revelers setting fire to an outdoor couch as a guitar strum builds in force.

Thunderbitch bears musical similarities to Alabama Shakes -- with blues, soul and country influences to a driving garage rock -- but tilts more to the heavier side.

Alabama Shakes hails from the small town of Athens, Alabama, and has won critical acclaim despite little glitz in the band's appearance.

The band is driven by the force of Howard, whose steely voice brings to mind male blues singers.

Alabama Shakes' second album, "Sound and Color," came out in April and debuted at number one on the US chart.

The band backed up the album with extensive touring, performing at major festivals including Coachella in California and Glastonbury in England.

It is unclear whether Thunderbitch, which first came together several years ago in Nashville, will also take to the road. A section on the band's website on touring said simply, "Maybe someday...?"