The harmonics for an open cone with slant length "L" are the same as the harmonics for an open pipe with length "L." When the cone is transformed through phases of closed-open conical frusta into a cylinder of length "L" closed at one end, the fundamental halves and only odd harmonics remain. A simple approach using boundary conditions is presented in order to understand this remarkable fact. A new free interactive HMTL5 application is provided which enables the user to hear the resonances of a complete cone transform into the pitches of a conical frustum closed at the small end, and eventually into the odd harmonics of a closed cylindrical pipe.