Audio: tempo (0:11)
tempo plays lo and hi congas at four different tempos: 64, 88, 112 and 128 bpm. The tempo figure shows the score. The tempo table shows the range of four tempos from slow to fast in beats per minute (bpm).
Tempo is the number of beats in a period. It is measured in beats per minute (bpm).
Tempo is musical speed. It indicates how fast or slow a piece of music is.
It may come as a surprise that there is no universal standard for classifying tempo. There is even little agreement about what is considered fast and slow. In the absence of anything concrete, the tempos in the tempo table are taken from the delightfully named Imperial Society of Teachers of Dancing (ISTD) which publishes them in its syllabus for Disco and Freestyle Dance.
Tempo is extremely important if you want people to dance to your music. You do not want to vary the tempo during a piece of music designed for dancing: the dancers will not thank you for it. There is much more discretion over tempo if your music is just for listening to and you can speed things up, slow them down, or pause temporarily whenever you feel the need.
There are upper and lower boundaries to tempo. The lower boundary is around 30bpm. At this tempo, the gap between consecutive beats is two seconds. Studies have shown that a listener has difficulty perceiving a rhythm when the gap between successive beats is more than 2 seconds. The upper boundary is around 1200bpm. At this tempo, the gap between consecutive beats is 50 milliseconds, which is the threshold at which two consecutive sounds merge into one. This is the same phenomenon that underpins the use of delay in sound processing.
120bpm is an excellent default tempo for writing rhythm. It is as good a starting place as any especially if you do not know in advance what the final tempo of your music will be. 120bpm is the default tempo in a lot of music programmes and apps.
The tempo of all the music in the guide is 120bpm unless stated otherwise.
One reason 120bpm is popular is that it is easy to calculate the duration of a beat or a group of beats. At 120 bpm, one beat occurs every half a second, 2 beats occur every second, and four beats occur every two seconds. These are easy figures to work with.
Another reason 120bpm is popular is because of the link between percussion rhythm and human rhythm. A normal human heart beats in the range 60-100 bpm. Exercise, such as dancing and running, increases the heart rate. Some researchers suggest that a tempo of 120-140 bpm is the ideal for moderate physical exercise. Sporty types who engage in hard physical exercise prefer higher tempos and many joggers and runners like stuff in the 170-190bpm range. 120bpm is a happy medium between extreme sports tempo and couch potato indolence.