Part of a wave of young Mexican guitar heroes, Julián Mercado flexes his considerable skill throughout Próximamente, nodding to the heartrending melodies of ranchera, the jumpy rhythms of norteño, and the romantic sophistication of banda. But he’s able to blend those diverse styles into a warmly inviting and casually inventive sound that’s all his own. Mercado exudes a beyond-his-years elegance on “Fuí Aguerrido,” gleefully navigates the tricky dynamics of “Lo Que Quiero,” and more than matches the explosive horns throughout “El Gallito.”