C. D. Major could refer to a number of subjects depending on the context. It could be a person's name, potentially standing for a fictional or real individual, or it could refer to a major chord in music. In the context of music, "C. D. Major" isn't a standard term; however, C Major and D Major are two common musical keys.
If you meant something specific about C. D. Major, please provide more context, and I'll be happy to assist!
