How RPM Differences Led to Beat Matching

DJ History: How RPM Differences Led to Beat Matching

The question went like this: Why did Technics invent a pitch adjust when they released the SL-1200MK2 turntable? This is a common myth amongst club DJ's - that the pitch adjust feature and beat matching in general originated when the "1200" was released. First, beat matching was introduced to the masses at New York's Sanctuary nightclub around 1969 by DJ Francis Grasso. Second, the pitch adjust feature - essential for beat matching - has been around for quite some time and can trace its roots to differences in rpm's (not to be confused with bpm's).

During the 1920's, hardened shellac records grew in popularity (gradually replacing Thomas Edison's cylinders) and were recorded at 78.26 rpm (revolutions per minute). Rpm refers to the total number of times a turntable platter revolves in one minute. The 10" 78 rpm record remained the industry standard until World War II, when shellac and other materials became scarce - propelling the introduction of plastic vinyl records as a replacement.

The 78 was also discarded because it played records too fast. For example, a 50 minute recording would require five discs. The word "album" originated from the way these packaged sets resembled photo albums. In 1948, Columbia introduced the "long playing" (LP) record (33 1/3 rpm) to get more recording time from a single disc. The length of the record was also later expanded to 12" to get even more music on each side. At roughly the same time, RCA released the 45 rpm "EP" (extended play), which typically provided four songs (two songs per side) - but was later shortened to the 7" single (SP). A "battle of the speeds" broke out between labels as each label sought to dominate the post-78 rpm market.

This created a dilemma for consumers since a separate turntable had to be purchased for every rpm speed (which could get quite costly). There were also recordings at 16 2/3 rpm, as well as very early recordings at 73 and 80 rpm. Hence, a true record collector in the 1950's would need a turntable to play records at 16 2/3, 33 1/3, 45, 73, 78.26, and 80 rpm. Turntable manufacturers wisely responded to consumer demand by producing "multi-speed" turntables, as well as "variable speed" turntables.

To play a record on a classic variable speed turntable, a listener would have to adjust the turntable's speed to find the correct rpm (since a preset option may not be available). In some cases, the listener would not even know whether the correct rpm was achieved. To alleviate this problem, the stroboscopic turntable was invented (see example H.H. Scott 710 Stroboscopic Turntable), where a strobe illuminator lights the peripheral edge of the turntable platter so that when the dots appear stationary, proper pitch is attained. It should be noted that a strobe illuminator is also featured on the popular Technics SL-1200MK2 turntable.

The variable speed turntable was essential to the rise of beat matching. Francis Grasso used Thorens turntables with variable speed to beat match in the 1960's. In fact, I phoned the technicians at Panasonic/Technics to collaborate this key point: the pitch adjust feature on the SL-1200MK2 is a vestige of the classic variable speed turntables when listeners needed to play records at different rpm's.

We are able to beat match because the recording companies of the early-20th Century engaged in a "war of speeds" by producing records at different rpm's.