A few more:

Louis de Meester (Belgium): Sinfonietta Buffa.
Alun Hoddinott (Wales): At least three Sinfoniettas.
Robert Hughes (Australia - not the New York-based art critic):
Sinfonietta.
Oldrich Korte (Slovakia): Sinfonietta.
Nikolai Rakov (Soviet): Sinfonietta.
Peter Tahourdin (Australia): At least two Sinfoniettas.

Richard Pennycuick
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