I was messing around on my guitar earlier when I came up with this little bit. Sorry if it seems like a dumb question, but when I sharpened the C note at the end it made this feel resolved. So I guess my question is what kind of scale am I using here? Why does that accidental at the end seem to resolve so well with it?
Good ear! You've come across a very traditional resolution, and it's a sign your ears are already tuned in to some of the important sounds you'll use in music.

But first, those are arpeggios, not a scale. A scale is linear. Those notes may all fit in the same sale, but that's because "scale" is a very broad category. Arpeggios are just chords played on note at a time, so they imply Harmony directly, just as chords would.

The important questions here are 1) What chords do these arpeggios spell out?, and 2) What Key are you in?

1) The chords are G#7 and C# minor (it's OK if you don't know what those mean yet)

Why? Interestingly, G#7 is spelled out by all but the very last note. G#7 is spelled G#, B#, D#, F#; and you have those notes clearly.

The first three notes "16 15 13" are G#, B#, and D#.

The next 5 notes "14 13 16 14 13" are just moving down the C# minor scale

The next two notes, skipping strings "13 14" imply a G#7 with an altered note in the chord (D##).

And the last note is the C#, the root of the scale, which is exactly the resolution your expects.

2) Because of this very clear resolution to C#, the key is C# minor. You know it's minor because of the notes E and A, which belong to the C# minor scale: C# D# E F# G# A B C#.

I suggest now looking up the basic Major Scale and Minor Scale formulas, and start working with those. As you get familiar with them, you'll start hearing other familiar sounds.
(cdgraves with the quick fingers beat me to it. :cool

tab out the notes man...

G# C D# A G# F# E D# C E C#

Then put them in order (any order) so you can see the notes and intervals...
G# A C C# D# E F#

Note: there are two different notes that use the letter C but we don't have any kind of B at all. Ideally we want to use all the letter names if we can so we can rename C by it's enharmonic B#.
G# A B# C# D# E F#

Comparing it to a normal major scale the sharps go in the order of F C G D A E...etc (circle of fifths). Here we have the F C G and D notes sharp which would suggest an E major or C#m scale if it weren't for that B#.

B# in E major would be pretty odd. However, B# in C# minor would be a major seventh (leading tone) which is the C# harmonic minor scale.

You already noted that you feel it resolves to that final C#. You just need to start looking at the "C" note as B# instead.

If you do then you will see the first three notes G# B# D# form a G major arpeggio. Then there is scalar run down from A (A G# F# E D#) that final D# is part of a major sixth shape (D# to B# = major sixth) which is followed immediately by another major sixth (E to C#).

That major sixth interval that finishes the lick is an inversion of a minor third interval.

If we take the B# and make it the lower of the two notes then we have B# D# -> a minor third built off the leading tone (suggesting a vii chord) which leads immediately to a C# E minor third which would be the minor tonic chord.

So yeah, short answer - C# harmonic minor. Even simpler answer - you're in the key of C# minor.

I've just taken a longer way to try to show why the B# is functioning as a B# not a C. I tried to show that it is a third above G# and a major sixth above D# and a major seventh against the tonic C#.

If we called it C then it would would have to call it a diminished fourth above the G#, a diminished seventh above D#, or a flat tonic - none of which are ideal.

So B# is the note, not C.
Quote by 20Tigers
You just need to start looking at the "C" note as B# instead.

So B# is the note, not C.

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I love to have my vag pounded by guys who make lame threads on the internet!

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This thread topic is gold. I've been on this website for 8 years and I've never come up with anything like this. So yeah. Great job TS[457undead].
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We already have C#; it's custom to not have two notes designated as "C". So, we leave C# and call C "B#".
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Knowing when to use enharmonic naming is a matter of context. In this context (C#m) the note is a B#. The rest of my post explained why you would call it B# instead of C. Is there anything in that specifically that you didn't understand?

Regardless here's a quick recap...

1. Ideally we would use all seven letters when naming the notes of a scale. Here we had two C notes (C and C#) and no B. So calling the C a B# gives us a different letter for note.

2. The rest of the notes and that it resolves to C# indicates that it would in the key of C#m. C#m usually has a B as a minor seventh scale degree. The minor seventh is often raised to a Major seventh when used as a leading tone. Thus a B raised a semitone is a B#. It's a major seventh, a leading tone, not a flat tonic.

3. A major triad is a root third and fifth. A third above some kind of G is ALWAYS some kind of B. Thus if we have G# then a third above that is B#. So as part of a major G# chord then the note is B#. C would be a diminished fourth above G#, we want a major third.

Also: cdgraves is spot on with his interpretation of the G#7 chord which is what this lick would suggest, a G#7 leading into a Cm tonic. Textbook harmonic minor.
Thanks a lot for your input guys.

It was that B# that threw me off from figuring out the key. Going from C to C# sounded so smooth and resolved perfectly, but theoretically didn't make sense to me. But all of your responses cleared things up. Thanks so much guys.