Hans Beek How fast should we play 17th and 18th century music?
Het ORGEL 102 (2006), nr. 1, 26-31 [summary]

We know rather little about the tempo of music in the 17th and 18th centuries. We have of course metronome indications – but those can be interpreted in multiple ways; we have, in a way, old ‘recordings’ in mechanical music instruments (clocks, carillons) – but they probably don’t reflect the tempo of ‘non-mechanical’ music making; and we have ancient dances, which of course can be executed only at a speed that the dancing human body can follow – but in the end, that doesn’t tell us much either. Sources such as John Playford (1654), who tells that we should take the tempo of a large chamber clock as a reference, or Johann Joachim Quantz (1752), who states that 80 units per minute is a proper tempo for an Allegretto, offer insufficient information on which to base solid conclusions.
Therefore it’s very important that a document has been discovered in the Archives at Groningen that indicates quite precisely how much time the Stadts Collegium Musicum in Groningen, founded in 1683 and active throughout the entire 18th century, could take for certain pieces. It is important that this source be studied properly by a musicologist, so that we will eventually know something really concrete about the tempo of music in the 17th and 18th centuries.