2.6 Good times and bad
By 1924 the burgeoning of radio broadcasting in the United States proved of great importance to the record industry. The sensitive microphones and electronic amplifiers used in broadcast studios offered improved characteristics that were exploited in the record industry through the development of an electromagnetic cutting head by the American company Western Electric. Electric players rapidly replaced the older machines, as they were able to exploit the improved characteristics of the electric recordings. In particular, the new recordings were able to use equalisation (i.e., the process whereby the volumes of specific parts of the audio spectrum are altered relative to the other parts of the sound) to improve the replayed sound quality.
Following the Second World War (1939–1945), demand for records increased dramatically. An example of the upsurge is demonstrated by the figures for sales of an early recording of a popular piano concerto, which sold 102 copies in 1935 and 62,756 copies in 1946. Consumers, though, were no longer satisfied with excerpts of symphonies or musical works shortened to fit to one or two sides of a disc. Record companies began to make full-scale symphonies and choral works available as sets, but the recording media were not particularly convenient or conducive to an enjoyable musical experience. For example, Bach’s St Matthew Passion (approximately 3 hours of music) came on eighteen double-sided 12-inch records, but listening to this work involved changing records 36 times!
In 1948 Peter Goldmark (1906–1977), head of research at Columbia Records in America, demonstrated a 12-inch (30 cm) non-breakable microgroove vinyl disc capable of playing 23 minutes each side. Columbia called it the LP (for long-playing) disc. It revolved at 33⅓ rpm with up to 300 tracks to the inch (120 per cm). The rival company RCA-Victor seemed not to be impressed with the LP. They responded with a 7-inch (18 cm) microgroove vinyl disc that revolved at 45 rpm, the so-called 45, which had a similar track pitch to the LP and played for up to 4 minutes. The ‘Battle of the Speeds’ commenced.
Fortunately for the record companies a truce was declared by 1950, with the 78 rpm disc the loser. The LP was adopted for classical recordings and the 45 for popular music. In Europe the change took a little longer, but by the end of 1952 LPs were available from European manufacturers.
The LP is not quite the end of the story of the gramophone record. As far back as 1931, the British engineer Alan Blumlein (1903-1942) designed and patented a stereo recording system that used two sound channels to create a virtual sound ‘stage’ where an individual sound source (instrument, voice, etc.) could be located at any point between two loudspeakers placed at the front left and front right of the listener. The location of the source is determined by the relative intensity in the two channels. The patent covered two possible ways of cutting the groove in the record to allow two separate channels to be recorded.
This brings to a close the story of the record (cylinder and disc), the main source of recorded sound for nearly a hundred years. Apart from refining manufacturing techniques, little change to the technology took place. Despite the recent up-turn in sales of vinyl recordings, other means of reproducing sound have long since come to the fore.