AC/DC in the context of Colin Burgess (musician)

Hard rock or heavy rock is a heavier subgenre of rock music typified by aggressive vocals and distorted electric guitars. Hard rock began in the mid-1960s with the garage, psychedelic and blues rock movements. Some of the earliest hard rock music was produced by the Kinks, the Who, the Beatles, the Rolling Stones, Cream, Vanilla Fudge, and the Jimi Hendrix Experience. In the late 1960s, bands such as Blue Cheer, the Jeff Beck Group, Iron Butterfly, Led Zeppelin, Creedence Clearwater Revival, Golden Earring, Steppenwolf, Grand Funk Railroad, Free, and Deep Purple also produced hard rock.

The genre developed into a major form of popular music in the 1970s, with the Who, Led Zeppelin and Deep Purple being joined by Black Sabbath, Alice Cooper, Aerosmith, Kiss, Queen, AC/DC, Thin Lizzy and Van Halen. During the 1980s, some hard rock bands moved away from their hard rock roots and more towards pop rock. Established bands made a comeback in the mid-1980s and hard rock reached a commercial peak in the 1980s with glam metal bands such as Mötley Crüe, Bon Jovi and Def Leppard as well as the rawer sounds of Guns N' Roses which followed with great success in the later part of that decade.

In baseball, a closing pitcher, more frequently referred to as a closer (abbreviated CL), is a relief pitcher who specializes in getting the final outs in a close game when his team is in the lead. A closer who successfully gets the final outs for their team in the final inning of a game is recorded as a save in baseball statistics. The role is often assigned to a team's best reliever. Before the 1990s, pitchers in similar roles were referred to as a fireman and stopper. Closers typically specialize in a breaking ball of some sort in order to minimize the risk of home runs late in games, and to deceive batters into swinging away from the strike zone.

In Major League Baseball (MLB), some closers have been noted for their use of entrance music when they jog out to the mound to warm up, often to excite the fans and to intimidate the at-bat. For example, the San Diego Padres of the National League (NL) played the song "Hells Bells" by AC/DC for closer Trevor Hoffman, and the New York Yankees of the American League (AL) played "Enter Sandman" by Metallica for closer Mariano Rivera.