Beware of appeals to divine powers. Agamemnon must sacrifice his daughter Iphigenia to appease Artemis so he can sail to Troy and slaughter some more. Idomeneo promises Neptune the first living creature he sees once he lands safely on shore, only to be welcomed home by his son Idamante. Jephtha vows that if God safely delivers him victory over the enemy Ammonites, “What, or whoe’er shall first salute mine eyes / Shall be forever thine or fall a sacrifice.” Of course, his only daughter Iphis steps forth most eagerly to celebrate his triumphant return. 

I have no progeny to slay in exchange for an ideal rendition of Handel’s Jephtha, and so in Jordan Hall Friday night, Boston Baroque’s mostly competent presentation left me craving catharsis. Under music director Martin Pearlman, the period orchestra and chorus approached Handel’s final meditation on destiny, justice, and mortal toils of righteousness with more artisanal craft than artistic vision, resulting in a performance more perfunctory than profound.

“It must be so,” the opening words of the oratorio announce its proto-Beethovenian theme, revisited verbatim as Jephtha struggles between his vow to God and horror of the consequent demand on the life of his innocent child. The valiant hero who liberates the Israelites self-identifies in his own probity. (“Virtue my soul shall still embrace, goodness shall make me great,” he assures himself in bright G-major triplet runs before he realizes what fateful and fatal choice between honor and compassion awaits.) His darling daughter Iphis inherits his values. She urges her beloved Hamor to fight “with double ardor brave” for the Israelite cause, then she herself with quadruple ardor brave and grace submits to her fate, as “too little is the price of one poor life” to purchase peace and blessings for her people. Her mother Storgè, arguably the throbbing human heart whose fears and fury fuel the transcendence of this morality play, refuses accept some cruel twist of one man’s “impious vow.” Storgè, Hamor, and Jephtha’s equally-but-differently moral brother Zebul beg for Iphis’s life, but tormented Jephtha will not budge. An Angel intercedes like Portia in The Merchant of Venice, dispensing legalistic mercy that droppeth as the gentle rain by pointing out that Jephtha can still honor his vow if he dedicates his daughter to God as a virgin for life. Depending on the version and cuts one employs, some if not all characters voice variable degrees of relief. Throughout, the chorus of Israelites — thoroughly Greek in dramatic function— pleads for, despairs of, and ultimately rejoices in heavenly mercy on behalf of humanity in general. “Whatever is, is right,” it repeats, with equal parts wry resentment, grim resignation, and aspirational rectitude, with the relentlessness of Fate’s door-knock in Beethoven’s fifth symphony.

As his vision rapidly deteriorated, Handel labored over this last oratorio longer than for any other composition. Coetaneous Bach had already died at age 65 the previous year as Handel grappled with mortality, morality, and destiny in Jephtha. Scholars speak of it as the closest approximation we have to the composer’s portrait of his innermost self, in which he musically inverts the pat piety and deus-ex-machina triumphalism of Thomas Morell’s libretto to introduce brooding ambivalence and draw sympathies to human suffering.

All of which is to say, Jephtha invites and deserves so much more than pretty notes on an even beat.

In the title role, tenor Nicholas Phan exhibited his customary careful musicianship, with the round refinement of a bowler hat, and plosive Ts crisp enough to hang it on. Within the constraints of the received canvas, he applied subtle shifts of coloration to his character’s evolution. From self-possessed confidence in the inherent justice of the world through despair at his moral dilemma, he rightly arrived at an endpoint where a tint of plaintive not-quite-believing haunts his grateful praise of God. “Waft her, angels,” Jephtha’s grief-stricken plea for the heavens to grant his daughter in afterlife the protection he himself could not, waxed especially poignant, each soft hitch on the first syllable of “angels” lodging another hook in the heart.

Soprano Ava Pine’s Iphis soothed with honey-and-lemon tea warmth, sweet but never cloying. A little more ebullience in Iphis’s early scenes and a stronger undercurrent of anguish through “Ye sacred priests … Farewell, ye limpid springs and floods” could have vaulted her character development to greater heights. Yet “Such news flies swift … Happy they!” effectively cleaved a quiet crushed-petal path to resignation of life and love.

As Storgè, Ann McMahon Quintero’s loamy mezzo-soprano embraced mourning like a down duvet in her first aria sending Jephtha off to war. The orchestra somewhat submerged the grit and gravity of her nightmare vision in her second, but her rage and haunted incomprehension of injustice charged through with Azucena amplitude in her third.

Countertenor Randall Scotting rang a bright and ardent, if slightly over-vibratoed, Hamor. The versatile bass-baritone Dashon Burton served honorably in Zebul’s musically and dramatically limited role, imbuing it with the moral weight of compassion, and spicing up his sonorous passages with the implausibly bright bounce of his Ns. Soprano Sonja Tengblad’s Angel glowed rosy as a Rubens cherub.

Although a little stiff at first, and mostly loyal to a workmanlike pacing throughout, the orchestra gradually extended its expressive reach as the evening progressed, excelling in purely instrumental passages. They could have applied the darker shadings of “Deeper and deeper still” more generously through other sections. Indeed, with greater imaginative depth and sensitivity to supporting the singers, they could have employed richer variation to help propel dramatic development. Both chorus and orchestra could tighten their attacks and cut-offs and mold more within lines. The soprano section requires a little reinforcement and finer focus.

All in all, to borrow from Jephtha’s own entrance aria, build on this steady base, and goodness could yet be great.