I'd call a DJ a musician if they are blending tracks in real time. Not transitions, but whole tracks. Like layering an a capela over another track... or blending tracks through a set. That's also about what percent musician they are: Can transition 2 house songs: 10%. Can blend 2-4 songs together live and nobody knows exactly what it will sound like in the next phrase... 100%.

I'd keep that definition to producers as well. Producing a track in Abelton, makes you a musical composer, and being able to blend that live determines what kind of musician you are.

This isn't meant to take away from anybody, and if you call yourself a musician... you are. It's just how I prefer to rank my favorites against people I hear in the wild. You're right, Disk Jockeys play the crowds as much as they play the tables, and everybody will have a different opinion about their mood setting. You can play 10 instruments, but if you don't move emotions nobody will care or remember.