Some science behind the scenes
Tala (Sanskrit tāla, literally a "clap") is the term used in Indian classical music for the rhythmic pattern of any composition. It has close conceptual equivalents in other Asian classical systems such as the notion of usul in the theory of Ottoman/Turkish music.
A tala is a rhythmic pattern of beats for use with a percussive instrument such as a drum. Each such pattern has its own name. Indian classical music has complex, all-embracing rules for the elaboration of possible patterns. Tala does not have a fixed tempo but must conform to the set pattern of beats and silences. Thus in a typical recital the tempo may change, but the rhythmic pattern does not.
Carnatic music is one of the oldest forms of Indian classical music and uses the Tala system. In Carnatic music each pulse count is called an aksharam or a kriyā. Talas also use a "missing" beat, known as khali (empty). The tala is defined by the number and arrangement of aksharams inside an avartanam. As the system is quite complex I will not go into too much more detail, but suffice it to say that the western musical notation for expression of duration has its equivalent in Indian musical notation, the difference being that the Indian system has no set ‘bars’ but ‘sentences’ comprising sets of beats and non beats of various duration.
Thus the concept of duration of notes is a fairly universally recognised one although in many Eastern systems the duration and pitch are separately described.
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