Melody7 cannot be ADSR enveloped like the other melody tracks, as it is a constant drone note. Only the note pitch (frequency) and amplitude is altered automatically. The drone note refreshes every 4 bars, so if you have sent another sound to the SuperCollider synth, the sound will change to the new sound at the start of the next 4 bars and will continue to change the frequency and amplitude as like the previous sound before.
So that the note is not an irritating hum. the amplitude is decreased by 10% every 0.125mS (at 120bpm 4/4, or every eighth of a semibreve or half a crotchet). This creates a slow amplitude decay as if it were an enveloped sound, but it continues to play with 0 amplitude volume until a note is to be played again where the amplitude is increased.
This new ensemble below also introduces a gradual increase whenever a new note is played. The amplitude increase is also at every 0.125mS and is an increase of 50%, which produces a faster note with a slower (10% decay).
#239. Drums introduced around 1:22 into the tune, which livens it up a bit. The Melody7 sound is changed a few times throughout the composition. Essentially this was a test of the new gradual attack of the Melody7.