I'm learning a song in the key of D flat. I know that any middle A within the song is flat. However, is a high A (above the staff) still flat?
Yes. The key signature of Db has a Bb, Eb, Ab, Db, and a Gb. Those notes are flat unless otherwise noted no matter the octave.
For any key signature on any staff, you will only ever see the accidentals written once in a typical pattern. The octave the accidentals are in are entirely based on the clef used, but apply to all octaves.
You can think of the key signature as a general guide to what notes belong to the key you are playing in. For example, in the key of F the key signature has a Bb in it. So it is telling you every B is flat and all other notes are natural in the key of F.
2I might add that "above the staff" or "below the staff" is entirely notational, and if you change clefs the same pitch is suddenly "on the staff" . Not to mention those little notations like "8va" . May 11, 2014 at 12:33
4Well, key signature are a notational notion.– ÉdouardMay 11, 2014 at 16:06
As others mentioned: key signatures are valid for all octaves. With one notable exception: scordatura.
Scordatura notation is sometimes used for bowed string instruments. In scordatura, the strings are tuned in an uncommon pattern. The notation, however, uses normal notes in a normal staff to indicate how a note is to be fingered rather than how it is supposed to sound (naturally this only works when the string assignment is unambiguous). In that particular case, the "natural" key on the different strings is different, and the key signature's accidentals are only valid at the pitch they are written.
But such scores are rather hard to come across.
Most scales are assumed to be octave-repeating, due to the way that we hear a similarity between notes that are an octave apart (the reason for this being that with many instruments, any note contains harmonic partials at the frequencies of all the overtones of a note an octave below).
This includes the diatonic scale, which is the scale that standard notation assumes (and that key signatures are most relevant to), and this is why key signatures are read as applying to all octaves. Hence why in your scenarios all 'A's will be flat unless otherwise indicated.
Incidentally, there do exist scales which are not octave repeating, e.g. http://en.wikipedia.org/wiki/Bohlen%E2%80%93Pierce_scale.
(adapted from duplicate question Are tonal (sharp, flat and natural) key signatures octave specific?)
If a flat or sharp occurs in a key signature, it means ALL notes with that letter name are affected. Not just the ones that are on the same line or space as the one in the key signature.
It helps to remember that key signatures were originally invented to save time, paper, and ink back when all music was copied by hand.
4It helps to remember that key signatures were originally invented to save time, paper, and ink back when all music was copied by hand. Nope. Before the printing press, the three "key signatures" you might run into were (1) no sharps and flats, (2) one flat, or (3) two flats, and the great time-paper-and-ink-saving method was musica ficta: implicit, unwritten accidentals. That is when music was written by hand, you didn't really have key signatures the way we do today, so you saved ink by not noting the accidentals. May 12, 2014 at 0:40
I don't believe that's the reason key signatures were invented -- they avoid unnecessary clutter for the reader.– slimJun 27, 2014 at 10:54
Truth is that it IS flat; however if you played A natural up high it wouldn't sound too bad because it's so far away in frequency terms. If it sounds "ok" then that's why.
Downvote? It's totally valid to play an augmented (sharp) fifth in a musical piece. I answered the question correctly. Apr 1, 2015 at 19:38
Of course - there's no 'invalid' in music - but whether it would sound OK depends on the context, not just the register. Indeed a low ♮A might sound great in some contexts. Apr 2, 2015 at 22:54
You implied that a high A natural wouldn't sound too bad. That was, I guess, if it was supposed to be an Ab instead. Then in the comment, it gets changed to +5, which is totally valid, but at that point, written as such, it is supposed to be played as +5, and will sound better than 'not too bad'.– TimFeb 9, 2017 at 16:03