Portland’s Mother Leopard and Belfast’s The Class Machine will perform an evening of rock ‘n’ roll Saturday, May 12 from 7 to 9 p.m. at the Bangor Opera House, 131 Main St. The 21-and-older show is free, hosted by WPC Presents and the Penobscot Theater Company.

WPC Presents, curated by Sasha Alcott and Chris Viner, pairs live, original music including acts from the Bangor area coupled with touring musicians. The series has taken place in a variety of establishments and recently expanded to include acts from as far as Pittsburgh, Pa. A new partnership with the Penobscot Theater Company is working on a WPC Presents music series at the downtown opera house.

Mother Leopard offers tunes are original and are influenced by grungy guitar sounds, ambient-to-funky keys, one dirty baritone sax, soulful vocals and a driving drum and bass. The Class Machine — power duo Nathan Raleigh (bass/vox) and Cody Tibbetts (drums/guitar) — describes itself as distilling a sumptuous liquor from the marrow of rock’s raw power. Lifetime rhythm section players, Raleigh and Tibbetts deliver gut-punch songs that put the bottom on top and make it play nice with shrieking melodies. And yes, Tibbetts does play drums and guitar at the same time.

Donations will be accepted at the event in order to both cover the costs as well as to support the Penobscot Theater Company. WPC Presents’ sales of books, CDs and DVDs at the event also will benefit PTC; anyone whose wishes to donate the same should send email to chris.m.viner@gmail.com or sasha.alcott@gmail.com.

Courier Publications’ A&E Editor Dagney C. Ernest can be reached at 207-594-4401 or dernest@villagesoup.com.