Engaging with the natural notes of the (French) horn.
Currently you will find educational videos as well as videos for playing along with. Duets, trios and larger ensembles minus a part so that the experience of playing just intonation intervals can be somewhat 'live'. The first in the series invites you to join me in a duet. Use the harmonics of the horn to achieve simple just intonation in a few standard chords in C major (concert F). Fingerings are suggested and the notation shows the major 3rds that should be narrower than standard 12-tone equal tempered intervals. The video is embedded below for easy access.
Notation uses the Extended Helmholts-Ellis Just Intonation system devised by Marc Sabat & Wolfgang von Schweinitz (see their detailed explanation at https://marsbat.space/pdfs/notation.pdf).
Some of the videos below have been renamed and are in the playlist Tuning the Horn https://youtube.com/playlist?list=PLj-3CaGOcPF0PYFll2X_gd7T8Yjb80v1p . They are for advanced players wishing to expand their knowledge, experience and skills.