Jim Marshall's famous black box allowed bands to be heard by larger crowds than ever before. Now, though, it's more a symbol of arena concerts than a necessary component of them.
I'm gonna play some heavy music/
I'm gonna play bad, I'm gonna play loud
- Blue Oyster Cult, "The Marshall Plan"
When Jim Marshall designed his first amplifier in 1962, he used the 12AX7 vacuum tube, a seemingly slight deviation from the 12AY7 tubes of the popular Fender amps—because Marshall couldn't find any in Britain at the time. This accident of geography meant that customers of his music store suddenly had a little more crunch in their guitar sound. In rock and roll—a genre forever entwined with technology—a mere vacuum tube begat a major shift in the music's history.
Marshall, who died last week at 88, also had the fortune of having a 20-year-old Pete Townshend for a customer. Townshend told Marshall he wanted to hear himself over The Who's audience and rhythm section. Thus was born the first 100-watt amp. Add to that two cabinets, each bearing four speakers—together, the components came to be known as the Marshall stack—and Marshall secured himself a permanent spot on any history-of-loudness timeline.
Loudness is strictly a psychological phenomenon referring to how the brain perceives the strength of a sound. But exactly why loudness appeals to so many of us is still a mystery. In his book, Your Brain on Music, neuroscientist Daniel Levitin suggests that very loud music saturates the auditory system, causing neurons to fire at maximum rates. Studies have shown that louder music causes us to shop more and work out more enthusiastically.
The joys of loudness are hardly confined to rock music, or this century. A 400-pipe organ built in 10th-century England required 70 men to play the instrument, which produced a thunderous tone throughout the city of Winchester. Digs of ancient ruins in Peru have unearthed instruments made from conch shells that could drown out a chainsaw.
But composers had few terms to describe degrees of loudness until the 18th century. "Piano" (soft) and "forte" (loud) and their variations became common features of notation, but they were frustratingly vague and subject to the performer's judgment. Thaddeus Cahill did away with such ambiguities when he invented one of the earliest electronic instruments, the Telharmonium, in the late 19th century. The volume control allowed the performer to choose any one of 24 degrees of loudness. It was a good idea, but the instrument bankrupted him and some family members.
TOWNSHEND'S WISH TO HEAR HIMSELF PLAY over his bandmates and audience was certainly a reasonable one. But his discussing it with Marshall—who could actually do something about it—might be the moment arena rock was born, and the start of a widening divide between audience and performer.
Concerts were held in large venues before there were Marshall stacks. But listen to the recordings of the Beatles at Hollywood Bowl: The screaming crowds are as much a part of the show as the band onstage. Fans were interacting not just with the Beatles, but one another; it became a participatory event. Not that the Beatles were happy about this. They stopped touring partly out of frustration of not being able to hear themselves. The Fab Four never had a Marshall stack; they stuck mostly with Vox amps.