Really Need Help: Relative Keys

[iamlegend]

Hey guys,

I'm new here and kindav wish I would've found this place earlier   , I have a question about Relative Keys.

I've came up with a melody I want to record a song out of using the Bb7sus4 chord arpeggiating between (eb, f, ab, bb), the thing is... there's no ab note in either the Bb major or minor keys. I've noticed that the relative key to Bb major is G minor (so says wikipedia), however there's no ab note in G minor either.

So how would I go about using this arpeggiated melody I've come up with while staying in key? I'd also be ridiculously grateful if someone could explain from a songwriters point of view how to use Relative Keys in conjunction (if you even can) when writing a song. Relative keys have been a gaping hole in my knowledge of the theory and it's catching up with me now, so hopefully someone could plz plz plz clear it up for me.

Thanks a million if you reply!

[ajspiano]

Your chord/arp belongs to Eb major.

[iamlegend]

Your chord/arp belongs to Eb major.

That's what I thought.. but then how come there's no Ab note in the key of Bb major?

[mikeowski]

That's what I thought.. but then how come there's no Ab note in the key of Bb major?

There just isn't. Why do you think there would be?

[ajspiano]

That's what I thought.. but then how come there's no Ab note in the key of Bb major?

The question isn't really relevant. Your composition is not in Bb major. If it was, the chord would be F7sus..

All major scales are constructed on the same set of relationships between scale tones, theres no Ab in Bb major because it simply doesnt belong.

Just like Ab doesnt belong in Bb major. Neither does your whole chord. in the key of Eb you have 7 basic chords, they are as follows..

Eb major, F minor,  G minor,  Ab major, Bb major, C minor and D half diminished.

your chord functions as an extension of the 5th or Dominant chord, Bb major.

[ajspiano]

on the topic of relative keys and how to use them..

every major key has a relative minor, its always 3 semi tones below the tonic in the major key. So in Eb major, the relative minor in C minor. This is the chosen relative because it's the most frequently used minor sound scales that shares the same key signature.

in classical music though, ! and other genres but theres a bit more explaining in the others perhaps,  The minor is often different from the major because the 7th scale degree will be raised one semi tone. this creates a harmonic minor scale.

often in composition we can "inform" the listener of a change to a minor key just by using this raised 7th degree..

for example, in Eb major if we raise Bb to B it will function as the raised 7th in C minor.

Here is 2 chord progressions.

stays in Eb
Eb major / / / | G minor / / / | Ab major..

transitions to C minor
Eb major / / / | G7 (contains a B natural) | C minor..