What kind of software/code do I need to use/access a file with the .TONE extension?

I'm very new to software development, I'm trying to access a handful of .TONE files that another app uses, the app was written in C or C++ I believe but I dont' have access to the source code and I can't figure out how to open or utilize the TONE files. They are literally just that, TONES for A, A#, B, C, C# etc. I will answer any other questions to the best of my ability and please let me know if this should have been posted elsewhere. Thank you!