Dance of the Blessed Spirits is a ballet excerpt from Christoph Willibald Gluck's opera Orfeo ed Euridice, which is based on the story of Orpheus from the Greek mythology. This was the famous flute solo found in Act 2.
The texture is mainly three layered: melody, chords and a bass line. Slow music is about resonance. The melody will be coloured and enhanced with plenty of well judged damper pedal effect.