Original: It was originally scored for a chamber group of flute/piccolo , clarinet ( B flat and C ) , two pianos , glass armonica , xylophone , two violins , viola , cello and double bass , but is usually performed today with a full orchestra of strings , and with a glockenspiel substituting for the rare glass armonica .
Simplified: Saint-Saëns arranged it for an orchestra consisting of flute doubling piccolo , clarinet ( B flat and C ) , two pianos , glass harmonica , xylophone , two violins , viola , cello and double bass .