Duple and quadruple metre

Duple metre

Duple metre is a musical metre characterized by a primary division of 2 beats to the bar, usually indicated by 2 and multiples or 6 and multiples in the upper figure of the time signature, with ,, and fast being the most common examples.
Shown below are a simple and a compound duple drum pattern.
\new Staff <<
\new voice \relative c'
\new voice \relative c
>>
\new Staff <<
\new voice \relative c'
\new voice \relative c
>>
Though the upper figure must be divisible by 2 in duple metre, the contrary is not necessarily true. For instance, in the first movement of Maurice Ravel's Piano Trio, the time signature is subdivided as rather than a subdivision. The movement is in odd time, not duple metre, even though the upper figure is divisible by 2.
Duple time is especially common in marches, where the duple meter provides a clear upbeat/downbeat feel that is suitable for marching. Duple time is also common in many styles including the polka, well known for its obvious "oom-pah" duple feel. Compare to the waltz, a form in triple metre, where the feel is an "oom-pah-pah" triple feel.

Quadruple metre

Quadruple metre is a musical metre characterized in modern practice by a primary division of 4 beats to the bar, usually indicated by 4 in the upper figure of the time signature, with being the most common example.
Shown below are a simple and a compound quadruple drum pattern.
\new Staff <<
\new voice \relative c'
\new voice \relative c
>>
\new Staff <<
\new voice \relative c'
\new voice \relative c
>>
The most common time signature in rock, blues, country, funk, and pop is. Although jazz writing has become more adventurous since Dave Brubeck's Time Out, the majority of jazz and jazz standards are still in "common time".