As a youth, Lars Ulrich swung a mean tennis racket. But he swung even better drumsticks.

Born the day after Christmas, 1963, in Gentofte, Denmark, Ulrich was the son of Torben Ulrich, an accomplished tennis pro from the late 1940s through the early 1980s. Lars was a quite a prodigy in the sport and at age 17 moved to Los Angeles to pursue his training. There, he ended up a drummer instead. He posted an ad in a local paper called “The Recycler,” met James Hetfield from that ad, and the two formed the now-legendary hard rock group Metallica.

It could be said that Lars got his musical genes from his father, as well. Torben Ulrich played jazz with such notables as Miles Davis and Stan Getz, and legendary saxophonist Dexter Gordon is Lars’ godfather. When the elder Ulrich obtained five passes to a Deep Purple concert in 1973 – and one of his friends couldn’t go – he took little Lars, instead, and though he was only 9, the boy was sold on rock-and-roll. The child bought Deep Purple’s “Fireball” album the next day, and by age 13, he was the proud owner of a Ludwig drum set.

Ulrich met up with Hetfield in 1981, and the youngsters formed an alliance that would not be broken, though some of the supporting characters have changed. With more than 90 million records sold worldwide and 57 million sold in the U.S. alone, Metallica is recognized as the best-selling thrash metal band of all time.

For his part, Ulrich has been a groundbreaker on the drum set. He became known for his fast thrash drum beats and techniques on many of Metallica’s early songs, particularly “Metal Militia” (from the “Kill ‘Em All” album), “Fight Fire With Fire” (“Ride the Lightning”), “Dyers Eve” (“… And Justice for All”) and “Battery” (“Master of Puppets”). His machinegun-emulating double-bass punch on the song “One” and the relentless pounding that opens the hit “Enter Sandman” are other examples of Ulrich’s unmistakable style.

While Ulrich created many fans through his performances and recordings with Metallica, he has turned off a few over the years, as well. He met with criticism in 2000 when he became one of the first and most vocal artists to take action against Napster, an electronic music-sharing service. Ulrich testified before the Senate Judiciary Committee, noting that Metallica’s entire catalog was available for free download via Napster. Though no lawsuits for copyright infringement ever resulted, the case was settled out of court, and more than 300,000 Napster users were henceforth barred from using the service.

Ulrich has been married twice, and has two sons, Myles (born Aug. 5, 1998) and Layne (May 6, 2001), from his relationship with second wife, Skylar Satenstein, an emergency medicine physician. A third son was born to Ulrich via his relationship with Danish actress Connie Nielsen; Bryce Thadeus Ulrich-Nielsen was born in San Francisco on May 21, 2007.