Programming Sine Waves in Scheme

    A. Summing Two Sine Waves:

        1. to get beating behavior:     listen     see

        2. to get a fused, complex timbre:     listen     see

        3. to get a multi-pitch timbre:     listen     see

    B. Amplitude Modulation (AM):

        1. to get beating behavior:     listen     see

        2. to get a fused, complex timbre:     listen     see

        3. to get a multi-pitch timbre:     listen     see

    C. Frequency Modulation (FM):

        1. to get beating behavior:     listen     see

        2. to get a fused, complex timbre:     listen     see

        3. to get a multi-pitch timbre:     listen     see