Take the Murguia family: Amalia and Alfredo immigrated from a small region in central Mexico to Kansas City, and had seven children, five of whom shared three beds in one of the house’s two bedrooms. Alfred, one of the older children, excelled academically and was the first in his family to enroll in college — and, at every stage, helped guide his siblings into a variety of educational and social opportunities. As Dominus writes, “What the siblings had going for them above all else was one another.” They “pushed one another but also provided logistical support, connections and counsel,” along with “unquestionable loyalty.”

Similarly, the Chens, who immigrated from China after having violated that country’s one-child policy, settled in Virginia, where they opened a restaurant. While the parents had high standards, they had little time to guide their children. Instead, their cousin tells Dominus that “when he pictures one Chen child playing piano, a sibling is on the bench as well, refining the younger sibling’s technique; they leaned over homework together, the older teaching the younger.”

In large measure, the families Dominus portrays are not particularly well off. But what she calls “enterprising parents” go to great lengths to expose their children to music, theater, museums, libraries and, most important, mentors. One of the customers at the Chens’ restaurant was the head of a high school marching band; he volunteered to give their child lessons — and that child became a drum major.

Laurence Paulus, a producer of arts television programming and of modest means, took his children to openings at the Metropolitan Opera. Unable to afford tickets, they sat outside the theater to absorb the charged atmosphere, a transistor radio broadcasting the music. They waited in line for free performances of Shakespeare in the Park; they played music at home. One daughter became a world-famous theater director; another, the principal harpist in one of Mexico’s premier orchestras; their brother would co-found NY1, one of the nation’s first 24-hour community TV stations.