On April 30th, 1977 – 41 years ago today – the English rock band Led Zeppelin set a new attendance record for a single-act, non-festival ticketed concert, when it played to an audience of 77,229 in Pontiac, Michigan at the Pontiac Silverdome, the capacity of which was a bit over 82,000. That information got me to thinking about the impact of amplification on the performance of music, particularly the amplification of music performed by the human voice. While the first microphones were developed independently by David Edward Hughes, Emile Berliner, and Thomas Edison in the 1870s, they were not employed in ballrooms and theaters to actually amplify a human voice performing live music until the very early 1930s. Up to that time, the largest possible performance venue for a trained singer was an opera house, and for most pop singers, spaces considerably smaller. Microphones and amplification rendered venue size moot; miked and amplified, anyone could be heard anywhere. Microphones and amplification also had a tremendous impact on voice type as well. You see, until the advent of amplification, the primary male voice type in popular music was the tenor voice. With its natural intensity and relatively high tessitura (vocal range), […]