You don’t hear of many female bassists, but Esperanza Spalding headlines in her dual role on vocals and “doolin bass.” With a shadow of Astrud Gilberto’s voice half a century ago, Spalding reminds us of a certain timeless sensitivity and sensuality. Esperanza is full of her name’s Spanish translation: “hope.” But, just because Spalding is the lead singer and bassist, make no assumption that the rest of the band is merely backup. Though it is undeniable that the 23-year-old plays with the lyrics in an unexpected, sincere manner, we cannot overlook the cohesion of her group, which seems to work so well.

While Esperanza is a mélange of Portuguese, Spanish, and English poetry, its musical fusion is even more diverse and delicately orchestrated. I’d say, Carmen McCrae plus Eliane Elias on the Black Orpheus soundtrack, with maybe a hint of Joe Sample. She walks up and down the neck of that bass with both arms locked—one with the band, one with the words she’s singing. And yet, she freely traverses from piano chord progression to cymbal decrescendo to Spanish guitar. Characteristic of the genre, everyone has his or her time in the limelight with a sui generis solo.

Being the youngest professor at the Berklee College of Music is a tangible mark of Spalding’s genius, but my only pseudo-criticism is that I look forward to hearing her voice become richer with age, specifically from living the meanings of the words that make up Esperanza’s lovely songs.