“La Romana,” one of the standout songs from Bad Bunny’s invigorating debut album, “X 100PRE,” begins with bachata guitar — nimble, quick, leaning toward the traditional. Before long, it’s bolstered by a booming, viscous Latin trap beat, and the 24-year-old Puerto Rican rapper begins his trademark exultations.

For a couple of minutes, he continues this way, a blend of excitable and boastful. Then comes the switch: a quick sigh, followed by a dembow beat almost twice as fast. El Alfa, the Dominican star of dembow — the close cousin to reggaeton — arrives for some tongue-twisting rapping, and Bad Bunny returns with palpable urgency and attitude.

This union of two of Latin music’s best-known stars is a wild romp. And it underscores what has made Bad Bunny so valuable over the last couple of years. He is a chameleonic figure, adaptable to almost any style, with a broad, blurry-edged voice that melts at the margins.

[How a new kind of pop star stormed 2018.]

In 2018 alone, he applied it to dozens of songs, including “Mia,” a tender come-on alongside Drake; “I Like It,” Cardi B’s neo-boogaloo stomper that became the No. 1 song in the country; the “Te Boté” remix, the reggaeton posse cut that was the summit meeting of some of the genre’s leading talents; and “Esta Rico,” a rather silly, but not ineffective, collaboration with Marc Anthony and Will Smith. His was the most pivotal pop voice of 2018, the common currency that everyone wanted to trade in.