Someone asked me this and I didn't have an answer.
When the Hot Club rehearsed / recorded a new number, a Django composition for example, who worked out the chords?
We know Django didn't know the names of the chords and the two rhythm guitars plainly play the same things. Did Joe and Eugene sit down together and work it out for themselves from the melody until they came up with something Django was happy with? Or was there someone else around who was able to tell them / show them "Dm, A7, Em etc, etc..."?