Now connect secondary cables to your bananas.
In section #1 the cables will go 2-3-4-5-6-7-8-9-A-B-C-D-E-F-G-H-I
In section #2 the cables will go 3-4-5-6-7-8-9-A-B-C-D-E-F-G-H-I
In section #3 the cables will go 4-5-6-7-8-9-A-B-C-D-E-F-G-H-I
In section #4 the cables will go 5-6-7-8-9-A-B-C-D-E-F-G-H-I
In section#5the cables will go 6-7-8-9-A-B-C-D-E-F-G-H-I
In section #6 the cables will go 7-8-9-A-B-C-D-E-F-G-H-I
In section #7 the only cable will be 8
Keep doing this until you've got your whole instrument hooked up so each banana has two cables coming out of it.
It's best to think of this as a base 18 number system with each section being the 10s, the 20s, the 30s, etc. The reason each section gets shorter is that in this Scratch project we have to avoid instances of including both 1-2 and 2-1 because Scratch will read them as the same command, same for instances of 1-1 or 4-4 since Scratch we register that as only one key press.