Derek E. Miller and Alexis Krauss of indie-rock duo Sleigh Bells perform at the 9:30 Club in Washington. (Kyle Gustafson/For the Washington Post)

My, how Sleigh Bells have grown!

The Brooklyn outfit delivered an assured, muscular performance to a sold-out 9:30 Club on Wednesday that bore little resemblance to the shaky, smoke-and-strobe buzz band of two years ago.

Supporting “Reign of Terror,” their recently released second album, singer Alexis Krauss and guitarist Derek E. Miller were joined by guitarist Jason Boyer (and 12 Marshall cabinets) onstage.

But beyond widening their sound, the Bells have learned to balance Krauss’s high-pitched warble (and rock-and-roll aerobics) with brawny guitar crescendos and precisely triggered spasms of strobe lights.

The smartly paced 45-minute set included just six of the new record’s 11 tracks and placed its best one-two punch — “End of the Line” and “Comeback Kid” — at the core. Everything around those songs played like a summary of the past two years: The spasmodic hooks of “Infinity Guitars” and “Kids” felt bolder, Krauss’s stage presence smarter and sassier — her vocals clawing but never quite grating.

And although “Reign of Terror” doesn’t deliver on the promise of its debut, Sleigh Bells have matured, displaying professional command of the current bag of tricks. The gleeful, bouncing mass of bodies that passed Krauss over their heads as she sang an encore of “Rill Rill” were clear proof of that.

That crowd didn’t much appreciate the opening set from Brooklyn-based Liturgy, despite it being far more intellectually satisfying than the headliner. The underground metal band appeared as a duo of much-maligned guitarist Hunter Hunt-Hendrix (yes, really) and guitarist Bernard Gann. They charged through a stimulating 30-minute performance of Hunt-Hendrix’s self-proclaimed “burst beat” metal and won over few Sleigh Bells fans in the process.

— Patrick Foster