Thanks, Laura, for getting that I wasn't praising that unfortunate prose describing the fictional meeting of Bix and Louis. My point was that he did have an exuberant side, chiefly focused on music most of the time.
It appears that Bix was rather more fortunate than we thought in the writers who chose to make him their main character. Perhaps Gerber's account sounds better in French (lots of things do, mais non?), but it appears that Berton and even Taylor (1929) were better as writers, at least when they weren't fabricating far-fetched episodes).
Your description of your friend's "Bix moment" suggests to me that perhaps these writers are projecting their own similar "Hey!" moments upon their subject. For a lot of us, that "Bix moment" of almost metaphysical "enlightenment" is a powerful memory, and perhaps Gerber's purple prose was describing his own reaction rather than Bix's jam session with Louis!