The Smurf Orchestra is the name given to the orchestra formed by the Smurfs in the 1981 cartoon episode "Smurphony In 'C'". The orchestra is usually conducted by Papa Smurf, though Brainy at times will take the conductor's stand. During the episode in question, Harmony tried to join in with the other Smurfs playing in the orchestra but was ejected from it when he played all the instruments off-key. Eventually, after Harmony saved them from Gargamel when he accidentally used the shazalla-kazoo on them, the other Smurfs allowed him to finally join the orchestra, as long as its other members wore earplugs to keep them from hearing Harmony's horn-playing.
In another episode, "Harmony Steals The Show", Papa Smurf brings the orchestra with him to contest Ghostwriter's claim of writing an original symphony for Harmony, playing out the entire symphony before the judge and revealing it to be an infringement of other people's works.
Also, the orchestra often appears in the intro sequences of the 1981 cartoon.
See Smurf Orchestra/Gallery for various images of the orchestra.