Four members of Mariachi Flor de Toloache perform at the US Consulate in Chennai, India, on Nov. 13, 2013. (Photo courtesy US Consulate Chennai)

Four women of Mariachi Flor de Toloache brought brightness *and* efficiency to bear at the 9:30 Club Monday as openers for The Arcs — a new band from The Black Keys’ Dan Auerbach of which they also are members.

The all-female mariachi band from New York City toured in a slimmed down line-up (which can involve up to 13 rotating members) of four, including vocalist and violinist Mireya Ramos, vocalist and guitarist Shae Fiol, trumpet player Julie Acosta, and a fourth member who I am sadly unable to identify for you. The four talented women sang songs from their self-titled debut album, and they brought spunk and spirit to the stage as an effective warm-up for The Arcs — well, effectively for themselves as well as the four blended seamlessly into The Arcs, providing vocals, strings, and horns as members of the 10-person collective.

Band founder Mireya engaged the audience with style and grace, asking Spanish speakers in the sold-out crowd to identify themselves. Although there were many delightful “Woo’s!” in the house in response, those with mastery of only the English language like myself need not have worried. Flor de Toloache played universally appealing material, and they led the audience along in several singalongs with cool aplomb.

Flor de Toloache conducted the audience through a chorus singalong of “aye, aye, aye” in their own “Cucurrrucucu Paloma,” a sweeping romantic track that combines the power of a traditional mariachi song with their female voices. They also make good use of this combination in their performance of mariachi standard “Guadalajara.”

Watch Flor de Toloache perform “Guadalajara” at Rockwood Music Hall in New York City on Jan. 13, 2013:
[youtube https://www.youtube.com/watch?v=zdXdp6HM1XA]

The quartet surprised early in their set with an extravagant cover of “Come as You Are” by Nirvana. Their mariachi-fueled take on the song is both flowery and haunting, engaging three of the women in harmonies that become particularly effective for the menacing refrain of “I don’t have a gun.”

They closed their all-too-short set with their own “Blue Medley,” a lovely, rolling selection that invokes an old-school happiness with its admiration of blue skies and bluebirds while saying farewell to “blue days.” The jazzy number, which mixes English and Spanish verses, was really quite idyllic and pleasant, and it demonstrated remarkable range for the ladies, who clearly don’t feel tied down by our expectations of a mariachi band.

During the main set by The Arcs, Mireya and company provided some terrifically appropriate atmospherics to the songs, particularly for “Pistol Made of Bones,” where they sing, play guitar, violin, and trumpet and generally characterize the pop-Western flavor that permeates the song.

Watch The Arcs perform “Pistol Made of Bones” live for NPR Music Front Row on Sept. 17, 2015:

[youtube https://www.youtube.com/watch?v=LtGdTuufB9I]

Mariachi Flor de Toloache and The Arcs only have four dates left on their current US tour, starting tonight, Dec. 16, in Philadelphia and ending Dec. 20 in Nashville. You’ll be truly enchanted and entranced if you seize this rare opportunity to see the ladies as both opener and main act. As Flor de Toloache are also up for a Latin Grammy for their first album, we will surely soon see more shows announced for New York City’s first all-female mariachi band.