turntabling is an art. Just like any other musician tells you, art takes time to learn and perfect. Whether its voice, guitar, clarinet, or percussion, they'll all say the same thing.
So now let's look at some arguments:
To quote from Wikipedia:
To people in many cultures, music is inextricably intertwined into their way of life. Greek philosophers and ancient Indian philosophers defined music as tones ordered horizontally as melodies and vertically as harmonies. Common sayings such as "the harmony of the spheres" and "it is music to my ears" point to the notion that music is often ordered and pleasant to listen to. However, 20th-century composer John Cage thought that any sound can be music, saying, for example, "There is no noise, only sound." According to musicologist Jean-Jacques Nattiez, "the border between music and noise is always culturally defined—which implies that, even within a single society, this border does not always pass through the same place; in short, there is rarely a consensus.... By all accounts there is no single and intercultural universal concept defining what music might be, except that it is 'sound through time'."
"There is no noise, only sound." "Sound through time." I think these two quotes sum up a lot. There is no set definition to what music is, hence the discussion we are having right now. But if you follow what the wikipedia quote states, then yes, disk jockeying is music, because it follows a "time" and creates sound.
However, let's go to Marty's argument:
Furthermore, IMO a person on a turntable is not a musician. A musician is more than someone who plays an instrument - a musician understands music. They understand Cadences, Rhythm, Chord Sequences, Key Signatures, Dissonance, Resolution, Syncopation, and a huge variety of musical knowledge in their head, even if they wouldn't know what to call it (e.g. Hendrix, who had a huge amount of music theory in his head even though if you asked him what he was doing he couldn't explain it). A person on a turntable need not understand any music theory whatsoever - they just need to know how a turntable works, and have a good sense of rhythm.
So according to what you say, a drummer is not a musician. Drumming does not require knowledge of chords or keys. But when you put a drummer with someone else that does, then you have music. According to your argument, a drummer would need more than a good sense of rhythm and the ability to hit things with sticks to become a musician. What if he does? Does that make him a good musician? Not necessarily. With practice, even a disk jockey would find what rhythms go best with certain music.
One last argument:
Well then, using that definition the Moog synthesizer - and every "synthetic" keyboard device since - is NOT an instrument, which I'm sure would be met with strong argument for the majority of the music world post 1969....
Correct me if I'm wrong, but doesn't the synthesiser make music that doesn't already exist IE it doesn't take a CD and muck about with the sound?
There are many types of synthesizers. My definition of a synthesizer is just a keyboard with a lot of add-ons. It can give preset beats, add in some drums, add some instruments, and you don't even need a full band! You could take music from a CD or disk and modify or add on to it. Does that make that person a musician? Depends. Since it takes its music from other mediums, you could say that technically it isn't an instrument, only a device that plays music.
I am a well versed musician. I have played music for almost 17 years now. I can play piano, french horn, trumpet, a little clarinet, and countless other instruments that I have a little bit of experience with, including voice (used to sing alto, but once puberty hit, became a bass). I have to say, becoming a disc jockey does take some creativity, while playing a instrument just requires you to read music that someone else created. Playing music does require some creativity, such as how to express it, but creating music takes a lot more.
Does that mean they're musicians? Perhaps. Scratching records provides a beat or rhythm that is added onto other music. But that's what drummers and guitarists do everyday; add on to what is already there. So going on that notion, I'd have to say that a turntable is not an instrument, instead its just a device. However, the disc jockey that uses the turntable can be considered a musician.