The Mandolin is often used in Spanish music.

In particular, the onstage mandolin band (known as the Rondalla) often
plays a part in the orchestral texture of zarzuela.  Rondallas also
included lutes, vihuelas and the like, depending on what was available.
The inimitable rondalla sound is as potent a seasoning to the Spanish opera
repertoire as the 'banda' to the Italian, and a far more subtle one at
that!

Anybody fond of the mandolin sound should check out Act 1 of Vives's
masterpiece "Dona Francisquita" (seen at Washington Opera last year) for a
classic use of rondalla.  There is an unusual and lovely in-pit use of the
mandolin band in the heroine's Act 2 romanza from Sorozabal's "Katiuska",
where the instruments imitate Balalaikas to evoke the warm Ukrainian spring
night.

Turina's famous "La oracion del torero" started life as a work for
rondalla, and though it is more often heard in its later orchestral
guise the original has a haunting beauty all its own.

Christopher Webber,  Blackheath, London,  UK.
http://www.nashwan.demon.co.uk/zarzuela.htm
"ZARZUELA!"