auto tuner to cennect with midi
how to build auto tuner ( pitch correction ) in pure data
rjdj has one, e_forcepitch, you can get it https://github.com/rjdj/rjlib
then you probably need to modify slightly if you want to use it outside of rjlib
it uses sigmund~ to get the pitch and the pitch shift example from the help files to do the pitch shifting.
what about fiddle ?