Oratorio
Oratorio

A large-scale musical work for orchestra and voices, typically a narrative on a religious theme, performed without the use of costumes, scenery, or action. Well-known examples include Bach's Christmas Oratorio, Handel's Messiah, and Haydn's The Creation

http://www.oldandsold.com/articles06/opera-44.shtml

http://www.wired.com/images_blogs/thisdayintech/2011/06/Handel_Oratorio.jpg
(needs to be Redone at home)

Continuo
Figured bass
Concerto grosso
String quartet
Baroque opera- recitative aria chorus
Vivaldi Purcell Bach

String quartet 

Chamber music 
Ensemble of music consisting of second and first violins, violas and cellos 

Ground bass- musical example pachelbel's musical canon
A repeated bass line. Repeated bass line, donsn't change

Continuo
Linked to ground bass, the part that is played by a harpsichord, (look up figured bass)a piece of music that has a figured bass.

Concerto grosso
Particular type with a small group of instruments that play as a solo in a bigger orchestra.
http://www.google.co.uk/search?hl=en&safe=vss&tbo=d&biw=1024&bih=672&q=concerto+grosso+definition&oq=concerto+grosso+definition&aq=f&aqi=g1g-v1g-j1&aql=&gs_sm=e&gs_upl=2662l6132l0l7090l11l9l0l1l1l1l542l1294l3-2.0.1l3l0