I was initially surprised that Jean-Michel felt it necessary to transpose the tunes into C and attached the tablature to the C setting. I suppose that this was to help G/C players in France play the tunes on the C row, but it might be confusing for people in the rest of the world.
Another curiosity: in the video for Gigue du père Mathias Frank starts the first part using finger 3 but when he gets to the repeat he is using finger 4 for the same passage. In the tablature a repeat sign is used, so you have the curious situation of finger 4 being indicated on the last note in the first time ending, sending the reader back to the start with finger 3 (on the same button), which is awkward and not what the tutor is doing (both times through the tune). Makes you wonder about the wisdom of telling people not only which button to press but which finger to do it with.
Anyway. Frank is a wonderful player, on the 3-row as well.
From Jean-Michel Corgeron who is not on this forum and who asks me to convey this:
In the foreword to the collection, on page 2, it is clearly stated:
"This collection offers 20 titles from the traditional repertoire and is primarily intended for all SOL / DO diatonic accordion players, the most used model in France. "
As for the Mathias Gigue, in A1, there is a reference (1) to the variation that indicates the change of fingering.
Sorry for my bad english !!
if you want to contact Jean-Michel : franchesconnexions93@gmail.com