Change the pitch of a wave file at runtime without changing the speed

For an experienced VB programmer, perhaps with C++ experience, I need VB code that uses a custom made C++ DLL or equivalent to change the pitch of playback of a wave file at runtime without changing the speed, without requiring directx, and without requiring specific sound cards. Perhaps at a low level the DLL would change these settings and provide basic playback controls. I would require the DLL to be password protected, compiled and source to be provided. Thanks. ## Deliverables C++ DLL or equivalent, with source and with password protection so my app can authorise its functionality only. VB example of how it work ## Deadline information I would need to see it fully working before it is finished.