<P> The nadhaswaram, nagaswaram, or nathaswaram is a double reed wind instrument from South India . It is used as a traditional classical instrument in Tamilnadu, Andhra Pradesh, Karnataka, and Kerala . </P> <P> This instrument is "among the world's loudest non-brass acoustic instruments". It is a wind instrument similar to the North Indian shehnai but much longer, with a hardwood body and a large flaring bell made of wood or metal . </P> <P> In Tamil culture, the nadaswaram is considered to be very auspicious, and it is a key musical instrument played in almost all Hindu weddings and temples of the South Indian tradition . It is part of the family of instruments known as mangala vadyam (lit . mangala ("auspicious"), vadya ("instrument")). The instrument is usually played in pairs, and accompanied by a pair of drums called thavil; it can also be accompanied with a drone from a similar oboe called the ottu . </P> <P> Nadaswaram is referred in many ancient Tamil texts . Silappatikaram refers to an instrument called "vangiyam". The structure of this instrument matches that of Nadaswaram . Since there are seven holes played with seven fingers this was also called as "Ezhil". This instrument, too, is widely played in Tamil Nadu and popular among the Tamil Diaspora . </P>

Which instrument is traditionally played in the indian marriage