MIDI pitch data in AIFF files?

I've been working on a simple sampler and started with the basic example in Max5/examples/sampling/sampling_with_adsr

Everything is fine with the example patches. However, when I load my own samples into the patch the pitch is completely screwed up and I hear a massively transposed version of the original. I dug into the patch a bit more and saw that info~ seems to be reading pitch data. The help file for info~ says, "Looping and tuning information is found in AIFF files."

I dig a bit deeper and see that cello-f3.aif seems to contain a MIDI pitch value of 53. I can't however, open this file in an audio editor to see this metadata. More importantly, I don't know how to add this kind of metadata to a new, custom sample.

I thought this would be easy to solve but no luck so far. Any suggestions?