Ruth Bader Ginsburg is known to be a classical music and opera buff, so music would seem to be the obvious vehicle for a tribute to the associate Supreme Court justice. But “When There Are Nine,” which had its exciting world premiere on Friday, Aug. 2, at the Cabrillo Festival of Contemporary Music in Santa Cruz, is more than just a celebration of the judge known as “Notorious R.B.G.”

It is also, as composer Kristin Kuster made explicit in her program note, a protest piece.

“When There Are Nine,” a 45-minute orchestral song cycle with chorus, presents a surge of principled outrage — by turns lyrical and ferocious, resolute and tender — against the inequities of the American legal and political system. It’s part biography, part anthem and entirely compelling.

Librettist Megan Levad cannily seizes on snippets of Ginsburg’s interviews and writing and presses them into service as vivid, imposing poetry. (The piece’s title comes from Ginsburg’s reply to the question “When will there be enough women on the court?”) There are, naturally, nine movements, each of them exploring some different aspect of Ginsburg’s life and career, and Kuster ensures that each one gets its own distinctive musical profile.

In the first movement, a set of wide-spaced choral harmonies, stoic but fragrant, introduces the idea of judicial writing as a form of literary criticism; the chugging, heroic rhythms of the final “A Push-Up is a Push-Up is a Push-Up” point the way toward a future, perhaps never-ending struggle toward righteousness. There are charming biographical interludes — a buoyant hymn to Ginsburg’s devotion to opera, and an infectious pop ditty celebrating her long and happy marriage.

But the great, overwhelming heart of the piece comes in the sixth movement, “On Dissent.” Here Levad lays out Ginsburg’s commitment to principled resistance to injustice, with reference to the long, gradual march of moral progress, and Kuster rises to the occasion with music of slowly arching grandeur.

Mezzo-soprano杰米·巴顿，为他们写的作品，一次表现出色，立刻进行了良好的探索，而演奏的人声八角齿的成员充满了礼物。音乐节乐团由音乐总监克里斯蒂安·梅拉鲁（Cristian Macelaru）领导，以口才和格蕾丝（Grace）演奏。

“When There Are Nine” — which was introduced by a videotaped greeting from Ginsburg herself — seemed a particularly apt centerpiece for an opening weekend in which the music of female composers was the predominant fare. Friday’s program also included “The Saqqara Bird” — a vivacious avian fantasy by Australian composer Melody Eötvös that bustled along with mechanized orchestral rhythms and chirrupy birdcall from the piccolo and flute — as well as Nina C. Young’s overstuffed orchestral tapestry “Agnosco Veteris” and Caroline Shaw’s Haydnesque “Entr’acte” for string orchestra.

For Saturday’s program at the Santa Cruz Civic Auditorium, I unfortunately arrived too late to hear either Du Yun’s “Kraken” or the world premiere of Anna Clyne’s cello concerto “Dance,” commissioned by soloist Inbal Segev. But Segev and Barton made a formidable pair of soloists for“The Work At Hand,”杰克·赫吉（Jake Heggie）向诗人劳拉·莫尔菲尔德（Laura Morefield）致敬，丹·德迪（Dan Dediu）的热情洋溢的“莱万特（Levante）”是罗马尼亚民间舞蹈和崩溃的黄铜奇观的混搭，使该计划得出了激动人心的结论。

Cabrillo Festival of Contemporary Music:Through Aug. 11. $20-$65. Santa Cruz Civic Auditorium, 307 Church St., Santa Cruz. 831-420-5260.www.cabrillomusic.org