The force of Lucius' singing defined their brief 45-minute set at Mountain Jam today.

Their songs were more powerful, leaner, and clearer than the versions featured on the group's debut album 'Wildewoman.' In a festival packed with musical acrobatics – the blowtorch blues of the Allman Brothers; the sustained jams of Grateful Dead descendants Ratdog; the ecstatic stage show of the Avett Brothers – this set was purely about the power of their voices.

Singers Jess Wolfe and Holly Laessig sing all their songs in total unison, note for note, harmonizing through choruses and verses. The effect was almost overwhelming on the quieter songs, like 'Don't Just Sit There.'

On the beat-heavy tunes (the group features an idiosyncratic percussion set up – there's no drum kit, but Wolfe and Laessig, as well as multi-instrumentalists Andrew Burri, Peter Lalish, and Dan Molad all have drums in front of them), the effect is more grandiose. When we caught up with Lucius backstage, they said their style came more out of a decade of singing and writing together than any particular outside influence.

Near the end of the set, Lucius even did a few bars of Whitney Houston's 'I Wanna Dance With Somebody' – appropriate, since their music is evocative of '80s sweatband pop's tendency to step back and let the vocals overwhelm.

Check out our Instagram photos of Lucius' performance at Mountain Jam:

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