French horn play along - Trio in Free Time Harmonics 4, 6, 7, 9

Part of the series "Tuning the Horn, engaging with the natural notes of the (French) horn."
Play each part in turn.
Horn 1 plays Horn in G (B-flat horn, valves 1 & 2).
Horn 2 plays Horn in D (F horn, valves 1 & 2).
Horn 3 plays Horn in A (B-flat horn, valve 2 and a little horn in G and horn in D).
The 8th harmonic of Horn in D = the 6th harmonic of Horn in G.
The 8th harmonic of Horn in A = the 9th harmonic of Horn in G.
The 4th harmonic of Horn in A = the 6th harmonic of Horn in D.
I'll explore other relations between harmonics in further videos.
Notated music in in-video.
A pdf of the score is available from the website: www.thebrasswhisperer.com