Why did records keep getting louder, and did it make them better?

Records got louder because a louder record stands out from the ones played around it. The loudness war is a trend of increasing audio levels in recorded music which, according to many critics, reduces audio fidelity and listener enjoyment. It was first reported as early as the 1940s, in the mastering of 7-inch singles. Jukeboxes were often set to one level by the owner, so a record mastered louder than the others stood out. From the 1950s, producers asked for louder singles so that songs would stand out when radio program directors auditioned them.

Vinyl had limits. Bob Ludwig's hot master of Led Zeppelin II caused some cartridges to mistrack, and the album was recalled and reissued with lower compression. The CD removed these restrictions. A CD has a clearly defined maximum peak amplitude, and once it is reached, loudness can be raised further with dynamic range compression and equalization. Engineers can compress a recording until it peaks ever more often at the maximum, called brickwalling, and in extreme cases that causes clipping and audible distortion. The industry believed that customers preferred louder CDs, even though that may not have been true.

Attention came in 2008, when Metallica's Death Magnetic drew mainstream attention for peaks pushed beyond digital clipping. A version without dynamic range compression, included in the game Guitar Hero III, was actively sought out by people who already owned the CD. Mastering engineer Ian Shepherd cited research showing no connection between sales and loudness, and that people preferred more dynamic music. By the late 2010s most major streaming services began normalizing audio by default. Not everyone agrees on how much dynamics were lost: Deruty and Tardieu found that the crest factor diminished significantly between 1985 and 2010, but the loudness range stayed relatively constant.