quote:

Originally posted by jefari 1. When composing your own song, your song must be defined by a scale, correct? Lets say C Minor in this example, which uses the pitches of C, D, E♭, F, G, A♭, and B♭ in its song. Is it safe to say a song with the key of C Minor uses only these pitches of the scale?

A song in C Minor will use mostly the pitches of that scale, but lots of songs still use ones outside the scale.

quote:

2. This may sound absurd and there is probably and obvious answer, but what would they key of a song be if it used all 12 pitches in an octave (piano) or would a musician never do this because it is not harmonic?

All twelve tones is called the chromatic scale. Using all of the notes with precisely equal frequency, i.e. writing a piece that does not favor any of the notes or center around a key in any way, is called twelve tone technique:

http://en.wikipedia.org/wiki/Twelve_tone

There are varying degrees of "chromaticism" or deviation from the ordinary "scale" system. Complete lack of any scale or centering key is called atonality.

Just remember that music theory is not a set of "rules" for plotting out a "correct" song, but a way of describing music that already exists. If you write a song in C Minor and throw in a Gb somewhere, you aren't necessarily doing something "wrong." It all depends on what effect you want to achieve.

Well, the first thing that you should know is that there are no absolutes in music. You're free to do whatever you want. That said, most people are used to hearing things a certain way, so whether or not something sounds "right" is more of a learned or behavioral phenomenon. That is why, for example, traditional Indian music may sound "wrong" to people who grew up listening to rock-n-roll - they have difficulty hearing the tonal center, familiar motifs, etc. in music that uses different scales than western music uses.

quote:

Originally posted by jefari 1. When composing your own song, your song must be defined by a scale, correct? Lets say C Minor in this example, which uses the pitches of C, D, E♭, F, G, A♭, and B♭ in its song. Is it safe to say a song with the key of C Minor uses only these pitches of the scale?

No, a song does not have to be defined by a scale. Music can change keys (i.e., move to a different scale with a different tonal center), or "borrow" chords from other scales/modes, etc. Also, in the case of minor keys, there actually three variations: natural (pure) minor, as you described above, melodic, and harmonic (you can google these to save me some typing!). That said, natural minor is most commonly used in EDM, with major being used fairly commonly as well, and Dorian mode to a much lesser extent. And, it's not uncommon to switch between the natural minor scale (e.g., Cmin) and its relative major scale (Ebmaj) or parallel major (Cmaj) in the same track, even in EDM. So, while the answer is that, no you're not obligated to stick to one scale, the use of natural minor is so widespread in EDM that the use of other scales/modes can sound out of place.

quote:

Originally posted by jefari 2. This may sound absurd and there is probably and obvious answer, but what would they key of a song be if it used all 12 pitches in an octave (piano) or would a musician never do this because it is not harmonic?

That's a tough one to answer because you'd have no way to define whether a given chord is major, minor, diminished, augmented, etc....and there would be no tonal center (i.e., root key). However, there are some experimental forms that use chromatic keys, but they don't sound like anything you'd hear in popular music and probably wouldn't go over too well with dance crowds.

___________________
cryophonik.com | facebook | soundcloud

Sonar Platinum | Ableton Live 9 | Logic Pro X | Access Virus TI2 Keyboard | Kurzweil PC3X | Nord Lead 4R | NI Maschine

Thank you both for your detailed answers, probably couldn't asked for any better ones! Though I may not fully understand them at this time, it does give me direction when trying to think it through in my head and I will probably have to refer back here sometime in the future when I familiarize myself more with music!

Cheers!