Amid a flourish of drums and bagpipes at 1 Police Plaza Thursday, Mayor Bill de Blasio swore in Bill Bratton as the 42nd commissioner of the NYPD and along the way gave the city a reassuring glimpse of his management style.

In sharp contrast with Wednesday's inaugural speech, the mayor sounded pragmatic and conciliatory during his first hands-on day as maximum leader of the NYPD and a total municipal workforce of 300,000.

De Blasio praised the NYPD's success at keeping crime rates low. It's our job to have your back, he told the cops.

The mayor has spent most of his career as a political strategist and elected official -- not as a top administrator. But as he assembles a team of tested managers like Bratton for key city positions, it's clear that he values wisdom, skill and experience over political ideology alone.

Bratton's immediate challenge will be to demonstrate that street policing -- including stop-and-frisk procedures -- can be done effectively and constitutionally. As he does so, he could soon face another challenge -- sharing power with a court-appointed NYPD monitor. If that unfortunate possibility happens, he must make the arrangement work without compromising the department's performance.

Carmen FariƱa, de Blasio's new schools chancellor, faces an equally tough mandate. A respected official in the Bloomberg administration, she must now find a way to give parents a stronger voice in a system of 1.1 million kids and 1,700 schools. Making the schools more flexible and parent-friendly has long been necessary. But it's hard to do in a system so large without creating chaos.

We wish her and de Blasio's other senior appointees all the best. They're a distinguished group that includes two former executive directors of the Port Authority, Stanley Brezenoff and Anthony Shorris.

If de Blasio can keep his lofty promise to close the city's income gap, great. But his mayoralty won't succeed unless the streets are plowed after every blizzard, crime stays low and the schools keep progressing.

Happily, de Blasio seems to be getting it.