Consider for a moment how extreme the scenarios in love songs would seem if they were played out in real life. From the stalkerish tone of The Police’s “Every Breath You Take” to the codependent downward spirals in Usher’s “Lessons for the Lover,” the language is that of possessiveness and desperation. But the songs on Sara Watkins’ second solo album, Sun Midnight Sun, come from an entirely different place: sure-footed, self-aware mutuality. It’s no mild, dry affair either, but an elegantly visceral and rhythmically surprising one. Watkins’ songwriting abilities have just about caught up to her sharpness on fiddle, but she’s still a baby songwriter next to Jackson Browne. Eloquently introspective old-soul and outwardly idealistic pop philosopher all in one, he’s embodied the modern singer-songwriter archetype as thoroughly and successfully as anyone. Browne has guested at the Watkins Family Hour — Sara and her brother Sean’s long-running L.A. live show — and he’s returned the favor by inviting her to open his acoustic tour.